> But what do people do if miners approve a fraudulent withdrawal that steals money from the sidechain? Sztorc's proposal is to engage in a user-ctivated soft fork (UASF) to invalidate the invalid peg-out transaction. This presents a huge risk in terms of consensus to the mainchain. The UASF in 2017 was a high-risk move that only barely succeeded and Bitcoin was much smaller than it is today. The larger Bitcoin grows, the more difficult such actions will be to coordinate.

cryptocoin

Hmm I still think this is a better solution than "Just make more Bitcoin to pay miners with", but I'm starting to see the problems with it. I don't know, maybe a maintenance fee in addition to the mining fee (or just take part of the mining fee) could be used to return coins to the coinbase to reward empty blocks (albeit by a much smaller amount than a block with a transaction in it) as to prevent an attack.