You get the same issue for cash. If I deposited 20k cash, I'd get 121 questions about where it came from, where are the receipts etc.

Fortunately I have never had this situation, but I think this is a question that should be taken more seriously.

It's a real concern for someone who wants to avoid kyc but also doesn't want to give themselves a headache in the future.

I think the only answer is record keeping "just in case"... But exploration and guidance on how to do this such that you can give records in the future without revealing more than you need to would be very welcome IMO.