Well, I know I very breifly touched on this before, but I had a couple ideas since then.

The built-in Finance App is basically useless. HOWEVER, it cannot be deleted. Off the top of my head, I dont remember how much space it takes up, but we might be able to make use of it?

Using a DoorsCSE routine, would it be possible to somehow overwrite the Finance app with DoorsCSE and hook it to be run as if it was the built-in app?

That would prevent Doors from being wiped out on RAM reset, and even full RAM/ARCHIVE reset.

From there, IF thats even possible, could a routine be made to prevent certain variables from being deleted? Maybe flag them as non-existent, or already deleted (so long as garbage collect doesnt clobber it)?

Im an Android programmer, so the hardware/memory/assembler side of calculators is a little over my head. Thats why Im asking here.

And of course, if someone wants to go back to plain firmware, then can always flash back an OEM copy of the system software, and everything will be overwritten. Back to stock.

The Finance app isn't really an app; it's built into the OS- you can't remove it. The best you can do is hide it from the menu (done by, for example, Omnicalc).

In short, none of this is feasible without major patching, and I don't think anybody cares enough.

To clarify even further, it only appears in the Apps menu because that was that most logical place TI could find to put it. It's not a real App, and its lack of removability has no bearing on Apps.

Ditto again. I feel both that it's a lot of effort to make certain Apps (or Apps with a particular header field) unremovable, and that that's a pretty user-unfriendly thing to do. At worst, it could make your calculator disallowed on tests like the ACT where your memory must be cleared completely at the beginning of the exam.