Manual or automatic payment linking to the backend


I would appreciate your advice on the following:-

1. We wish to offer clients the option to pay during the appointment booking process or pay when they have had their treatment.
2. I appreciate I can set 'required payment' to 'Yes' but this would force all clients to pay when making the appointment.
3. I've found a related post: where Hakan suggests setting the 'required payment' to 'No' and then adding a PayPal payment button.

Before I progress this option I would appreciate if you could confirm if we do as in item 3 above, would it be reflected in the A+ backend if the client has clicked the PayPal button to make a payment?

If this doesn't work is there a shortcode we could use to replicate the functionality of the PayPal API but using the PayPal button?