Request - USIM/ISIM JavaCard Repo Access

Hi Osmocom Team, Long time listener, first time writer. Short Version: Would it be possible to get the source for your USIM/ISIM JavaCard applets that are installed on the sysmoISIM-SJA2, please? The Alternative: I've been researching a method to give my JavaCard applet default installation, and if my applet doesn't support the ADPU command, then it will revert back to your USIM/ISIM applet. Unfortunately, I have not found a solution. If you know of one, this would solve my ADPU update problem. Long Version: I've been looking into how SmartCards work and got interested in SIM card pertaining to JavaCard applets. I am interested in creating my own ADPU commands while still supporting all other ADPU commands that USIM/ISIM provide. Given the awesomeness of your products and dedication to open source research, I was hoping you can help me by providing the source. This way, I can overwrite the USIM/ISIM applets on the sysmoISIM-SJA2, and support my new ADPU updates. BTW, I looked/searched for these in your github repos and could not find these applets. Let me know if this is possible. Thanks for being awesome! -- Jeremy S.