Sounds to me like a very ill-informed individual JMHO... My 11yr old PD 9245 converter charges charges the LiFePo4 perfectly so long as I skip equalization (float is unnecessary and inconsequential) - Boost voltage is perfect, nor do I say this in the form of cavalier ‘Bar Talk’ - for me, always lots of results oriented empirical testing and meter data here...
As far as the inverter goes, his unqualified concerns are strictly a non-issue, in fact Li is waaaay friendlier to inverters and other downstream 120v devices simply because the voltage plateau remains relatively constant throughout the entire discharge cycle - this benefit tends to drastically reduce voltage sags and dreadful equipment killing current spikes normally associated with reactive loading... Chemically sluggish Lead acid batteries exacerbate this malady...
The poor Newmar fella is waaay out of his lane here...Better to avoid mysticism and stick with the empirical science...
I sent you a PM...
Upon edit, maybe I should send him a box of incandescent bulbs - lol