Unlicensed games on licensed cartridges

Is it possible to put an unlicensed game on a licensed donor cartridge?

For example, I've read that the Codemasters/Camerica games try to circumvent the lockout chip by trying to glitch it by sending electrical impulses etc. And I won't put such a cartridge into my NES since I don't want it to break anything.

So, let's take for example the game "Stunt Kids": Is it possible to put this on a regular NES cartridge? And if yes, which ones would suffice?

Several boards simply have disable switches. E.g. http://kevtris.org/mappers/lockout/camerica.html — if the switch is disabled, the stun voltage is simply not being sent to the NES. Of course, if it's a front-loader and you haven't disabled its CIC, then that won't work. (Otherwise, Camerica's games are usually but not always compatible with UxROM)

For the rest, e.g. Color Dreams & AVE ones, you'll basically have to rebuild it from scratch (or remove the stun and maybe add a CIC)—there is no licensed mapper that is sufficiently similar. Or INL has a mapper 11 reproduction-maker PCB.

Color Dreams games are on a mapper equivalent to nibble-swapped GNROM. There aren't many GNROM games (Dragon Ball/Dragon Power, Gumshoe, and Thunder & Lightning are pretty much it outside Japan), and games tend to have bigger CHR ROM than GNROM's maximum.

Do Color Dreams games rapidly switch among CHR banks, or do they use one bank and stick with it? You could run a game in a debugger and see how often bits 7-4 of the value written to $8000-$FFFF change. (Bits 3-2 are the CIC stun, and bits 1-0 are the PRG bank.) If CHR banks don't change rapidly, it'd probably be straightforward to hack a game to oversize BNROM in the same way that I hacked Solar Wars to UNROM. Then you could use any Rare AOROM game as a donor, as converting AOROM to BNROM involves cutting one trace from the 161 to VRAM A10 and adding one wire from PA10 or PA11 to VRAM A10.

Is there any reason to believe that these cartridges can actually damaged an NES? A lot of people seemed to be concerned that it might hurt their NES, but I've never heard a report from someone who thought it actually had.

You could just use a flash cart (e.g. PowerPak) to play these games, which would completely bypass the issue, if there is one. If you disabled the lockout chip on your NES, you could just disable the stunner on the cartridge, which would probably be a lot easier than trying to transplant the ROM. If you want to use new parts, INL's boards should do, or RetroUSB's discontinuned ReproPak might be good enough?

Yeah, I am curious how they could damage the NES. Presumably the CIC can be killed by them.

To disable the stunner, I think it's sufficient to remove a transistor or capacitor. They seem to be some kind of switching power supply (namely, a voltage converter for the negative pulse). No power, no pulse. Tape it up inside the cart so you can always just add it back if you want a more faithfully authentic unlicensed unauthorized cart.

An alternative is to harden your NES against the pulse, if you want to leave the cartridge alone or not have to modify your entire collection of unlicensed games.

How it could ≈permanently damage an NES:
Option one: a completely dead CIC makes the NES unbootable- it'll either hold /RESET low, or /RESET will float high before Vcc is high enough for the 2A03 to work. The only way to fix the latter is to use the reset button ... but the reset button is processed in firmware by the CIC.
Option two: If the cartridge is in at a funny angle, pins 34 and 70 could short out to pins 33 or 69, exposing the PPU's data bus to the CIC stunner's negative voltage.