None, however they'd lose out on all the economic activity that drives the value of POS ethereum long term. And they'd lose the same economic activity drives th

None, however they'd lose out on all the economic activity that drives the value of POS ethereum long term. And they'd lose the same economic activity drives the value of what they forked; and presumably that would cause a drop in value and less transactions; both of which are an incentive for miners to do something else with their resources. That economic activity consists of all the smart contract/web3/whatever you want to call startups that are currently building solutions based on the main Ethereum network and the investors/traders/opportunists backing them by speculating on the value of their coins/NFTs/etc or the value of their solutions. Most of those companies will probably benefit from the improved scalability and reduced cost associated with POS; or even require it to be viable at all. At least I would expect this to be true for the ones with some ambition to actually deliver working products; which are probably also the ones with the most investor backing. Of course, many more serious applications switched to alternate blockchains because of the scaling issues with POW might now consider switching back. And additionally, improved scale associated with POS might bring some new companies with investors as well. So, I would advice people to just follow the money when speculating on the future value of any fork. I suspect that won't stop anyone from creating that fork and you should actually anticipate multiple parties doing this and claiming to be the one true fork with varying degrees of credibility to trick people into buying some of their forked ETH. That's just how pump and dumps work and there are plenty of opportunists active to make that happen. And of course a fork means there are plenty of people not interested in the fork that would end up selling their forked eth so they can buy some more actual eth. Lots of people selling and not a lot of people with a good reason to buy means forked eth is not going to be worth a lot. Miners are going to run whatever has the highest yield. That probably is not going to be a forked Ethereum. Probably it's more lucrative to switch to some other POW blockchain (doge, bitcoin, etc.) if you have any serious amount of hardware. Disclaimer: I don't hold any Eth and am not really into crypto investing. Ironically, that makes me a more reliable source of information because I have no stake in this game.