Thanks for reaching back out, @erick.futuretale.
I hear you and realise the importance that this feature can have for your business. You've got me here to help share some information about developing our product.
The memo field on the banking section, can be used to all transactions that were manually entered in QuickBooks. However, we aim to help our customers run their business easier. That being said, we are constantly uncovering ways to make the product work the way your business needs. We're adding features based largely on the suggestions of users, like yourself.
As we strive had to develop the product, I'd recommend visiting our QuickBooks Online Blog to be updated with our latest news and enhancements.
Also, I've added here a couple of resources that you can visit about some "How do I" questions in QuickBooks Online for your future reference:
I understand the inconvenience that this has caused you, but your patience while this has been assessed is much appreciated.
Please know that my doors are always open to help you if there's anything else you need with QuickBooks. Wishing you and your business continued success.