The WFCO converter, if meeting its specs, will do just fine as a battery maintainer.
Battery electrolyte stratification is rarely a problem with A-frames - the slightest jostle every month or two from wind (if stored outside) or opening an access door is enough to take of stratification. Plenty of battery jostle while towing or camping.
Sulfation occurs when the battery is left in a discharged state for months on end, and is easy to prevent. Don't store your A-frame without recharging the batteries.
There are 2 methods of storage after recharging - both work well. 1) Disconnect the batteries with either a disconnect switch that disconnects ALL loads or removing ALL wires from one battery terminal. The batteries will take months to self-discharge significantly, especially during winter. 2) Leave a trickle charger attached (WFCO converter in trickle mode is an example). Some people have deep prejudices against one method of the other - both work well for me and many others.
Do test your WFCO converter - both of mine failed to go into trickle mode. After 44 hours in normal mode (13.7V), and no change in battery load, the WFCO converter is supposed to drop into trickle mode (13.2V). If the WFCO doesn't go into trickle mode, the extra voltage will "boil" the batteries over time (we're talking weeks and months), causing them to run low on water. If not caught, low water levels will kill a battery quickly. Don't ask me how I know.
If the WFCO is working correctly, the only real reason to change converters is to get faster charge times when charging with a generator.
My battery maintenance practice is: upon return home, plug in the A-frame for a few days to fully charge the batteries. Then disconnect the batteries until a day or 2 prior to the next trip (or doing something inside the A-frame at home). I normally plug in the A-frame at least the night before to pre-cool the fridge and top off the batteries. I do check the battery water levels when I plug in before the trip, and top off as necessary with distilled water.
hope this helps
2019 Flagstaff T21TBHW A-frame with 2 Costco/Interstate GC-2 batteries
prev 2014 Rockwood A122 A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time