Hmmm.... odd one would, sell a "correct" look repro battery for an old car, (at big $ for the restoration market) and then require modifications to the electronics. Never heard that one, but maybe so. Don't recall manufacturer docs with it making mention of that aspect, but will re-read to be sure I did not miss something..
No bench charging, just installed and running. Voltage at idle is flicking from 16.6-17.4... so high.
I am not an electrician, but am handy... but wiring is the one area I loathe, chasing electrical gremlins is a PITA I prefer to leave to others, but am ok to tinker around testing or replacing "bolt in" parts to deduce a bit of the issue...