the way I see it, the mods actual answer is, "yes, you can app, but you will be accepted depending on the quality of the app including the quality of 'whether this app convinces us there is enough material for a playable character according to whatever our game standards are'" which is different from "the quality of the app generally/normal app standards". The mods are willing to consider it, but after reading OP's app they might well decide that OP doesn't make use of minimal canon in a sufficient way, and they don't want to deal with a tantrum of "but but but you said it was enough canon to app from!!!!!!" if that turns out to be the case.

It's a frustrating answer, because yeah, you might do all that work and not get in, which is what OP was asking to avoid, but it doesn't seem hand-wringing to me. The mods don't have all the information, so "maybe" is the most straightforward answer they've got.