Yes, that is correct. In my case, the max size gen we can carry is the 2200 and it runs max at 1700VA which is what the 75 amper wants, so 75 amps is our max amps no way around it. (In the woods, no solar to add more amps)
There is not a single advantage to get LFP in our situation. No weight issue, got enough AH , Gen time is ok. What we have works, no problem for our situation.
There can be situations where an RVer can take advantage of LFP for weight, space, usable AH, etc, but "faster charging" is too easy to be misleading. An RVer must use some actual numbers for his comparison with what "speed" of charging he would get anyway using ordinary batteries, so he is not fooled by the advertising.
He may find that like us, he is gen size limited to a charger size that means no "faster charging" by enough time that makes his life better.