Your Seguro Trongle X4 is a budget-class set-top box, I wouldn't put too much time nor money in trying to restore it back into working condition. Get a Firestick, Chromecast, or Roku, they're actively supported and developed, and will allow you to interact with various streaming services in a more up-to-date way.
As a side note, doing a Factory Reset would not remove the Kodi app, it was manufacture-installed, system-level app so it's a preinstalled part of the Android firmware that's running on your X4 -- i.e. the Kodi app was present before you did the Factory Reset and would have still be present after the Factory Reset if it was successful. A Factory Reset only wipes the user data partition clean, it doesn't do anything to the other system-level partitions, where the installed operating system resides. If you did use the Factory Reset option in Recovery Mode instead of the option in the Settings menu, did you also experiment with the other options? If so, that might explain why it's stuck in a boot loop. Also, in one of your posted screen captures it shows an ADB message, did you delete and or alter anything via ADB? But whatever, I'd still suggest you just focus on getting a newer, better set-top or streaming content device. Life is too short wasting time on some things. And if you are averse to Kodi (I find that puzzling considering its capabilities), don't buy something with it pre-installed
https://phreesite.com/best-kodi-boxes/