I don’t disagree with any of your inputs and I truly wish I could customized the Redarc Manager30’s charging profile to lower its voltage to more manageable values, but there it is…
14.4V is what I have to work with (there’s no changing that charging system, though I guess I can contact Redarc about it).
I guess you need some top notch batteries for the Redarc stuff!
The other element of course is selling grade B cells under grade A advertising from once reputable vendors.