Insightful post, thanks for sharing!

One assumption that I disagree with (if I understand it correctly) is that if BU signaling clients get 80% of the hashrate, that that implies that “the market is saying that it’s pricing BTU at $800 & BTC at $200, effectively”.

In my view mining hashrate always follows price, and not the other way round. That’s what I’ve seen in the altcoin markets and with ETH & ETC.

So to me, if the price is $1,000 pre HF even though the market has priced in the HF, that doesn’t say anything about how the value will be divided among the two chains post-HF.

Because I don’t agree with the assumption, I don’t follow the calculation where the combined hypothetical value of both coins should be $400 in your scenario.