Your WFCO converter will charge the BattleBorn, but possibly not to 100% because it will come out of bulk charge mode too quick. You can call BattleBorn and they can walk you through everything, they are very helpful and have great customer service. You could upgrade the battery and then upgrade the converter later.
I replaced our WFCO converter with a PD4655L Wildkat, since our factory converter was 55 amps, you would need to check the model number on yours to determine the proper amperage required. Changing the converter is very easy since with this one you can keep the factory 12V fuse panel. With this converter it charges our BattleBorn batteries at 14.6V until it gets them up to 100% SOC when set to Lithium mode.
The bigger issue is the wire size that the factory ran between your converter and battery, which is likely 8 AWG max. So even with an upgraded converter you're still going to get some substantial voltage loss through the small factory charge wire. This is why I moved our batteries inside to the back of the trailer about a foot away from the converter and used 1/0 cable for all of the positive and negative wiring. We get a full 55 amps when the converter starts charging and then it tapers off once it approaches 100%. We can recharge very fast. Smaller charge wire will just result in slower charge times.
With a LiFePO4 battery I would highly recommend some sort of battery monitoring system, we use a Victron BMV-712 and are very satisfied with it.