Eventually that leaves the load to the source event if it’s differed. And the load would still grow along the growth of the fediverse. So this would likely be pushing the issue to tomorrow. Signing content checksum isn’t exactly like reinventing a wheel, it’s something done in many contexts. And it removes the load from the source entirely.

Yeah there must be some trust indeed of the og instance. A scoring system could help with that.

Add metadata with a checksum of the og one with signature and let each client check that up.