You'll have more luck searching in Kuriimu's github repository
BTW, according to the "Releases" section, it seems they have support for CTPK files since 2017. In theory, if you grab the latest stable version (v1.0.14), you should already have support for this kind of file.
Anyway, if you're having issues editing CTPK files on a specific game, I'd recommend you to take a look at the "Issues" section. You could search if someone posted an issue similar to the one you're having, and if you don't find any, you can post your issue there by yourself.