Looks like a very good combination.
1. Starting with 117V, not 123V like from a Honda Eu2000i. I wonder how this affects the PD's charging abilities? Does it make a difference, or is it the shape of the sine wave that makes the difference with the PD chargers?
2. AGM batteries at 300 Amp hours, and a Charger of 55 amps or a ratio of 1:5.8 or 5.9 charger to battery amp ratio. Not too much charger for the size of the battery bank. Pushing the % SOC up before going out of bulk charge mode, albeit at a slight increase in running the charger, time wise.
3. Fat wires, where it really counts, and not much voltage loss to the battery. Again, less resistance, keeping it in bulk charge mode longer.
4. AGM batteries, with again, less internal resistance to taking a charge efficiently.
Nice work, OP! Very, very efficient charging combo you have assembled there.