Friction was always a bs explanation
It didn't explain why sanji could turn off diable jambe at will or keep it as long as he wanted without even getting burned by it
My guess is
Sanji's power just blooms over time
At first he couldn't create fire but had some control over it (kinda like Pyro from the x-men) so he had to use friction
Then he got stronger and learned to just burst into flammes on top of controlling fire
I don't think it's related to the modifications, given how he had it before awakening his genes
It didn't explain why sanji could turn off diable jambe at will or keep it as long as he wanted without even getting burned by it
My guess is
Sanji's power just blooms over time
At first he couldn't create fire but had some control over it (kinda like Pyro from the x-men) so he had to use friction
Then he got stronger and learned to just burst into flammes on top of controlling fire
I don't think it's related to the modifications, given how he had it before awakening his genes
Oda said he wasn't burned because his passion burns hotter. Seems like the best answer we'll get from Loda tbh imo
This all ties back into sanjis introduction. He fought pearl who was essentially using a fodder tier version of hell memories.
He talks about how a cook can't be afraid of flames. I always thought he'd get a flame power up because of that