As promised, from the posts here and here - I made separate posts for the other "elements" of the main issue.
The full sequence of button clicks is captured in the here so I won't re-type all that in this post. The issue is that the "You got paid" → "Apply Payment" → Select payment to apply ALWAYS results in a "No Open Invoices" screen the first time I click to apply a Split Payment, so applying Split Payment always takes extra clicks when navigating the dialogs. The sequence is always:
I would like to see a fully populated list of Open Invoices the first time to eliminate Step "b." from the sequence above.
Permission Problem You need the session.valid permission to do that.