Set it up for both thanks for sure!

I like one full tank and then 1/2 or less in the second tank just in case. I run through a tank many times and needed just a tad more out of the second one.
Off set you weight by putting the full tank on whichever side you need weight to be perfectly flat.
2 full tanks are not needed and are extra weight, but one sometimes doesn't cut it.

I do remember a day that my tad wasn't good enough and Red drug us back in as the wind upstream was stronger than the current and the trolling motor wasn't enough to buck it either.