MPPT Controllers

I’d stick with the display type, and add a Victron BMV state of charge meter to gain a complete understanding of your overall systems operation... But I’m not clear on your controller inquiry... If you add a second controller to an existing system the problem that often occurs is the two controllers compete with each other (often called ‘dueling controllers’) due to conflicting output voltages... Better to just have one controller when possible, else do a kinda workaround and try say a single-stage type as a possibility to minimize dueling...Others may have some experience with this malady as well.

But when adding panels, attention should be given to having like kind output voltages, else the higher voltage panel will default to the voltage of the lesser panels voltage...A minor difference won’t matter too much - just saying...