I don't recommend exceeding the specs on those little PWMs.
As for the battery charging current, from what I see online the manufacturer recommends charge current to be under 30A for a single battery. With two in parallel, each or your batteries will be receiving half the charge current. So if you're pushing 36A into the bank, each would be getting 18A. That is a nice charge rate for the gels.
The simplest way to make sure you are splitting the current evenly is to wire your batteries up as shown below. Your charge sources and load devices should all connect to the positive terminal of one battery and the negative terminal of the other:
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