Do we really need to split bitcoin the currency?
A compromise with the Bitcoin Network/Blockchain would be better IMHO.

As far as i can tell, the majority is not comfortable with EC blocksize let alone BU.
On the other side I think UASF without 51% miner support is dangerous, because miners could just fake support for UASF and just orphan all blocks, which would actually include segwit transactions, while still adhering to the rules of the UASF/segwit.

So IMHO UASF does not safely work under given circumstances and EC has not enough economic support to do a safe HF.

An incomplete thought:
Why not add emergent consensus on blocksize through soft forked extension blocks and 1MB+segwit on the main blocks?

Another compromise could be main block 1 MB, extension block Core with segwit and max 2.7 MB blockweight and extensionblock with EC blocksize.
So when you'd run core, you'd have the same spam attack surface as with segwit now.
Of course this would mean more work for devs, which want EC, but the potential reward is higher.

The beauty for BU would be that afterwards you could hard-fork on that extension blocks all you want, without having the risk to split the base BTC currency.

P.S. my personal favorite is SBTC with RSK ;oD

Yeah.. I don't even know which side you are referring to
Seems to me that this is true for extremist on both sides.
I'm more or less comfortable in the middle of this mess.

Not entirely of course, but the relationship can be weakened

Lol sapeggitt ;oD
Yeah the beauty is that you only have to softfork once if you prefer hardforks and than can hardfork the extension blocks chain all you want without having the danger to double the BTC amount.

While segwit may be a compromise beetween small blockers and normal blockers, it completely disregards big blockers and as we can see through segwit readyness signaling also provides little incentive (or even negative) to miners.

I don't think core devs would love this. They would have to compromise too...
Devs are pretty smart - it would be no problem to implement this, the question is do they want to and if this is an acceptable compromise.
Unless devs for one extension block don't fuck everything up, they should always be fungible with real BTC through the main block.

The overall fungibility might even improve because downgrading the bitcoins back into main blocks could (would likely?) be implemented with free mixing.

In essence you could upgrade your bitcoins from the main block utxo to an extension block utxo.
Downgrading of course is also possible, although technically slightly more difficult.

Of course to send btc from a therotical EC extension block to a theoretical segwit extension block this could take some time, but this should be alot faster than if we split into two chains and you would'nt even be able to do this, no, you'd have to go through an exchange.
And than you'd of course have services like we have today with shapeshift, which would reduce the number of needed downgrade/upgrade to other extension block chain alot.

As a normal user your wallet could do that for you automatically.
The complexity could be wrapped through different adresses for the different extension blocks.

Its a bit like Lightning BTCs. When you have locked up your BTC in a channel you cannot use them otherwise. But the other party may not accept Lightning so you may find yourself in a dilemma.

So we would be better here from a user experience too compared to a split - and most settled transactions would be intra extension block.

You could design the basic idea of extension blocks in a numerous ways.
The most advanced document I found so far is this, though the document may slightly differ from my idea
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-January/013490.html



It is not ideal, but it I like it far better than status quo, contentious HF or UASF, which are the most popular ideas atm.

Thinking further ahead, I don't think we will end up with endless different extension blocks.
Each extension block has to provide clear advantages over what we already have.
Segwit and EC blocksize should both have enough interested people.

For the digital gold people, who only want to HODL this would be completely opt-in.
You could still use plain bitcoin 0.12 and receive bitcoins, completely ignoring the extension blocks.
Nobody would force you to use segwit or submit to EC.

It is not a perfect solution, but the best I currently can see. I think it is feasable, morally acceptable, makes HFs easier within the extsion blocks, preserves node decentrailization, allows miners to let onchain compete with offchain and most importantly does not split the currency bitcoin.

It does not need the permission from every development team. BU could go ahead, team up with Classic and do this without Core, if they would get support from the miners.

On the negative side i would create a little technical debt in the beginning, because you'd have to support extension blocks.
But later you would be saved from additional technical debt and could even pay off some.
E.g. if EC extension blockers deem segwit technical debt they do not need to support segwit.

Of course - an uncontentious HF would be cleaner, but due to politics from all sides will not happen in the next years.
For me this is so much more appealing than a chain split.

Funny thing is - because they use a completely seperate blockchain (which is merge mined with bitcoin) i suspect the oposite.
The higher the fees on the main chain - the more incentive for users to go to the sidechain, where we can easily have 100 tps onchain.
RSK will have a two way peg -> 1 Smart Bitcoin (SBTC) equals 1 Bitcoin
But atleast initially RSK has a very different (trust-) model than plain BTC and will need completly new software.

Nah you are jumping one step ahead. This is only a raw idea.
If you'd have support from miners and would SF the logic into main blocks, you don't have to lock the bitcoins.

So how would this work without locking bitcoins:
One simple solution would be to hold them in a special address on the main utxo and the user adresses on the extension utxo.

All miners still mine the main blocks.
EC miners additionally mine ec blocks. Segwit miners also mine segwit blocks.
A lot of miners will mine both, because they want to have the fees.

This would require 51% of the miners of an extension block have to be  honest, because only they know the rules.
So having 51% of all miners would be advisable.

When we compare this to a chain split scenario this is not worse, because there we also need 51% of the complete hashing power, to be safe against reorgs.

Sidenote:
I think a reorg on the main chain would only induce the same reorg to the extended blocks, because they are completely synchronized, if the logic of utxo selection for the downgrades is deterministic (think replay attacks) - this is where extension blocks differ from sidechains, where reorgs on the main chain are a huge problem.

Lol yes - Feels a bit like everybody knows, but nobody cares enough or all are just to afraid.
One obvious solution is to not have the debate, but to solve the problem it in a way which does not need permission from everybody, preferably not altcoins  

Edit:
Please compare this to a split chain scenario. Essentially your bitcoins are then locked forever in the other chain ;o)
Of course you can sell them, but with extension blocks you could do this too.

Locking would only be needed, when there are not enough miners mining the specific extension blocks, to be safer against reorgs / double spends / replay attacks on the main chain -> See my post above. This is where the simple idea ends and the engineering starts