Is the Filter Theory committing the ad hoc fallacy and is it unfalsifiable?

Agreed. But it's a start. I find all analogies to be ultimately incomplete, as they're based on our inherently lack of understanding how it all fits together.

We don't actually know how bodies have been designed for a mind to interface with them. It is totally unconscious only to the conscious aspect of the incarnate mind, perhaps... so maybe that unconscious aspect has its own awareness... well, it must, I would cautiously assert, because it is part of our being that drives the whole process. Else, the body would fail.

I feel like the idea of a VR headset + controllers + haptics console may be the best analogy though it won't be perfect.

The game you are logging into is a shared online virtual space. (This world)

Damage to any of the console components can interfere with your experiencing of said virtual space, even removing your access completely. (Physical damage & death)

There could be some kind of secret background program (cheat codes? glitches? power ups?) that allows you to do things not usually allowed in the virtual space. (NDEs, Psi)

A software and/or hardware error (or computer virus) may make you think allies are attacking you, or dialogue that was supposed to come from friends has been altered so it seems that they now hate you. (Mental Illness)

Skills that you are training for, saved conversation points, or your quest log may not actually update for your avatar. (Mental Illness)

Sometimes you go up a level or a particular skill gets a huge stat boost. (Sudden Savants)

And so on...it's not perfect but I think with some imagination it can cover by analogy the basic idea of brain illness in addition to the soul-body separation, Psi/NDEs, etc.