Hi there Rinne!
Love your apps
About CHHM2 I've had lots of issues with themes that are damaged or have some sort of special character, crashing my theme set and corrupting the themes cache.
Best solution for this is to select a system theme, and then installing your desired theme through CHHM2.
Last time, something happened (not sure what) and after some time fiddling with chhm2 and nintendo theme selector I got stuck in the black screen at boot. So I had to insert the SD card in the computer and manually delete the themes folder (000000008f)
So I ended up thinking that maybe you could add a function in the start menu to delete the themes cache folder. That would allow us to purge the themes and try again without the hassle of removing the sd.
Would it be possible?
You may need to add a warning note stating that the user will need to select a random theme from the default theme selector before accessing CHMM2 again.