Same cart across all Square apps

I use the Square for Retail and the Appointments apps at my ceramic shop.  If a customer wants to book a class as well as purchase physical items I have to use the Retail app for the physical items to complete that transaction.  I have to then go to the Appointments app to book their class and complete that transaction.  Also, I have a the Square Terminal connected to my iPad that I use as a card reader.  When a customer books a class the Square Terminal isn't an option for payment.  I do have the option to enter their credit card manually.
This is frustrating!  I'm not a software developer, but it seems it would be possible to fix this.