You're suggesting that Mighty is a full convection vape and it is not, it is described as a hybrid.
Imo the fan is your lungs and diaphram. I do understand your suggestions about draw, but most of the mild restriction in Mighty is from the cooling unit. Bypassing the c/u, with wpa for example, frees things up a lot.
More air volume, from a fan, would require bigger heat units and different electronics in order to be able to create vapor fast enough. Otherwise the effect would be diluted vapor (too high an air-to-vape ratio).
The fan would be additional drain on battery.
I have a Splinter V1, a textbook convection vape (I believe, btw, that
@OF would say all convection vapes are mis-characterized...but that's a different discussion). Anyway, my point is that by it's design, this Splinter has almost zero draw restriction when used in its' standard configuration.
For a user who has respiratory troubles, maybe a bag-type vape like Volcano is more appropriate.