For what it's worth, I've used FFOF, many times and never burned any of my plants or seedlings. It's not strong at all. Ask PhilKind.
You don't mess with the KindSoil, you put it on bottom, something else on top.
I've done it both ways, transplanting an also plant straight in final pots, and l like final pots a lot better than transplanting, regardless of all the transplanting ideas. Some transplant ,some dont, not a big difference either way, I ain't in no hurry anyway.
I like to start autoflowers, in final pots.Everyone does things differently.
Ps, plus I think PhilKind has been growing longer than, most everyone I know, and he has tried it all, on top of his Kindsoil, he says FFOF, is not hot at all, it's got bugs and usually the ph is way off.
Read some of his articles ,and you will see, what he thinks, and he's been right too.
He is constantly trying, new soils, to see what works best on top of his Kindsoil, he likes coco-loco, an RootsOrganic, last time I checked.