I was thinking recently that it would be more fitting to use the hash of the block or at least the last x number of digits of the hash. Anybody can say a block height, but you can't fake that hash.

nostr:nprofile1qqswaptqf78vde8zf78272nzf5zza02rrkhyfrlpzau6mnakhdu9whsppemhxue69uhkummn9ekx7mp0qy2hwumn8ghj7mn0wd68ytn00p68ytnyv4mz7qg3waehxw309ahx7um5wgh8w6twv5hsqex56d is what made me think of it.