Do you know of any discussion regarding the following opcode? I believe this could be helpful when dealing with timeouts happening in the lightning network, potentially saving onchain fees and/or avoiding onchain transactions.

With CLTV you can specify "this output is only spendable after block X", and I'd like to having something along the lines of "this output can only be spent before block X".

I already see issues with chain reorgs, as transactions cannot be copied over to a longer chain. It also makes template construction more complex (validation steps have to be repeated?).