I find memorized transactions to be extremelly difficult to work with. There are many issues that arise from them
1. Memorized transactions tend to trigger scripts and other automations that they are not intended to trigger because the field values set on them keep being copied over to new transactions
2. You cannot easily update the transaction information for each memorized transaction. For example, if memorizing Invoices for subsription services or something similar if you use legacy tax the new Tax Rates do not get used on future transactions even if you update the tax tables
3. Making changes or edits to memorized transactions usually requires you to delete everything and start again