Overhaul and upgrade to MPPT 150/45 + MultiPlus II 48/5000/70-50 - any feedback?

Buy another panel and connect them 3p2s. Always try to balance the series and parallel.
Your combination of 4 panels in parallel and these in series with only another one is quite strange.
When batteries are in series, the final current is 200A at 48V. So C10 is 20A.
Panels Isc is 40.60A, on your (strange) configuration.
When in series, the current is not adding. Voltage is adding. Ohm’s and Kirchhoff’s laws.
But don’t know if that single panel in series could handle the parallel current of other 4.
Take a look here: Overhaul and upgrade to MPPT 150/45 + MultiPlus II 48/5000/70-50 - any feedback? - #2 by alexpescaru