About the capabilities of modding a jailbroken Kindle

I just heard of the new jailbreak method.
I'm not particularly interested in KOReader or tools that completely change the functionality, but I want slight modifications like:
- overwriting the translate API to use Google translate or DeepL
- having the "wikipedia" mini window show custom results like from ChatGPT
All modifications are to be made in the built-in reader.
I want to know if these modifications are possible, even if no one's done it yet, I'll try to do it myself.

Any information would be appreciated.