On-chain gifts may be hard to move if not of significant size. If it was me I think a Liquid seed carved in steel for a small amount would be good, or a regular Bitcoin seed carved in steel (I'd just set either up on a Jade). You can gift them just the metal seed with the amount & instructions to recover it via the free default Liquid/bitcoin software they can download & run on any computer, or you can gift it with a Jade too which they can restore & setup for themselves. And just tell them to treat it like cash & keep everything in a safe.
Discussion
Not a bad idea, I just feel like they are nowhere near tech savvy enough to even comprehend this, much less do it.
You don't think they are gonna need you to get money off of an opendime too? I mean if you expect them to ever hand over the whole amount like cash, the seed plate is just as good IMO.