Yup, divestOS allows for booloader lock though unfortunately they don’t support microG. I hope they somehow help upstream their relock solution to LOS. I use LOS for microG instead, since I need stupid bank apps and also for the office some stupid proprietary multi factor authentication apps… If only LOS for microG could lock the bootloader at will (it needs to be unlocked for major upgrades, like on regular LOS), that’d be great.
There’s as well CalyxOS, which uses microG and also locks the bootloader, however I do prefer LOS since the strategy from CalyxOS and GrapheneOS trying to deGoogle pure Android in my mind sound like having some limitations, as opposed to LOS approach to be based on AOSP instead. Though that’s just in my mind, I’m sure those guys in Calyx and Graphene are the best at security and privacy.
That’s great if not having to use any proprietary apps depending on google services, including push notifications, since part of divestos unsupported stuff includes:
Which is fine, if you don’t need to use such apps. An alternative to /e/os, which now a days is actually murenaOS, is lineageOS for micro G, which does sort of monthly releases based on whatever is available as nightly releases on lineageOS. It does provide you with microG and also with F-Droid with privileged extensions installed and already set for you. This might be more suitable than divestos if in need for some such apps.