thanks @sunsetsystems for promising improvements to the checkout and payment screen that could go along way with some of the usability issues, like payments entered with encounter id of zero and copays not posting to the ar_activity table
before we recreate this thread, https://sourceforge.net/p/openemr/discussion/202504/thread/ea6efc26/?page=0
a core feature that could be addressed is batch charges. there was a recent post on the forum asking about this, Billing multiple days of service