This is how memo.cash is materially contributing to progress of bitcoin blockchain. I remember these rejected txs were due to high memo activity.
That chain is local to each user of memo, so it can happen to you only if you do more than 25 actions before a next block is minted, and you have only one UTXO at your address.
By splitting the UTXOs, so that each user have several confirmed coins at the address. Or by warning the user "You are doing it too much. Slow down a bit' ;)