More often than not, I manage to only get one MPPT by turning charging off/on.
The voltage range (few volts <60 to few volts >60) seem pretty narrow for that trick to work, so once I get one going, the voltage is often too high to get the other going, so up the roof I have to go again.
The other issue for me, is that once the batteries are fully charged and it ramps down to 0w, my 150/85’s will not be able to start back up again when there is demand.
It seems my problem is somewhat related to yours but not really so maybe I should just create a new thread.