I asked about this only because you asked about your unlock_ability=0. Looks like the trick is the opposite, to disable USB debugging and Developer options.
Anything said on the FairphoneOS install page ?
“Late Lockers” (by which I mean those who do not perform the lock immediately after install, without reboot as said on the /e/OS install page) face a difficulty of ensuring the correct device state … I did a little research and made this proposal Installed 3.0.2 official and tried to lock bootloader - #5 by aibd. Please read the two links and the follow on explanation by @olli0371 of how he moved forward.
Those dates show that you are progressing forward in SPL dates so no rollback hazard appears.