You can already do this with their custom css. I did it for about 5 minutes and then realized paying $99 was the right thing to do. It's a reasonable ask on their part.

I don't know about Immich, but in other FUTO projects you click the "I've paid" botton and it's disabled, even if you didn't pay. FUTO licensed code says you can't remove the pay button in derivative works, but Immich is AGPL so that doesn't apply.

So we need to make a patch then. Not great but fine.