Pruning first then on chain memos

The legacy thread for reference: payment ID / Memos

Once the pruning problem is solved it will be safe to add on chain memos. On chain files, tokens, NFTs etc all require persistent account block history. Pruning takes that away. Also with the savings in ledger storage, it would be no extra cost to store legitimate uses of the memo field.

So the main point: If we solve pruning we can safely add on chain memos.