:D it keeps track of the unconfirmed UTXO chain and if >25 switches to another UTXO. If you only had 1 UTXO you would have a cap of 25. But you have a lot, so your cap is high.
Thanks for the explanation, that clears it up. How many different UTXO can it change to? (Or: What is the upper limit of memo transactions per block?)
