I would worry about rich people being able to use this nefariously. For example, I could make Escrovery requests for a whole lot of bitcoin accounts with large balances (which I can see on the blockchain) and just hope that enough of them don't respond in time to make the costs worthwhile. If for example the escrow fee is 1% of the value of the wallet, and I do it for 100 accounts of roughly similar value, I only need 1 of the 100 to not respond to break even, and 2 of them to come out ahead.
So it will be very important to set the escrow value high enough to prevent this but low enough so that people who have legitimately lost their account can still recover their own accounts.
Users could probably select their own escrow, right?
For me, I'm not tying up the majority of my net worth in a single crypto. I could set an escrow at double the value of my wallet. It's highly unlikely that I do lose my secret key, and if I do, it'll be a huge pain to come up with the escrow, but it'd be doable.
And of course, you could probably set a cap so that even an in extreme spike of values, the escrow won't ever reach an amount that's infeasible for you.
I'd assume that doing this would rarely (but sometimes) be successful, but that alternately, there will be people putting large accounts out there in order to tempt this sort of speculation, and that side wouldn't be risking anything other than being forced to hold assets in bitcoin.
It'd wash out in the end.
Those 99 that didn't work out gave everyone you tried it on a 1% return.
So it will be very important to set the escrow value high enough to prevent this but low enough so that people who have legitimately lost their account can still recover their own accounts.