To note, the monthly security updates DivestOS provides don't (can't?) include baseband and such "firmware" updates for legacy OEM-unsupported versions of Android.
Don't get me wrong, it's terrific that security patches are backported to such ancient versions of Android by those working on DivestOS and it's a great option for devices that aren't supported by GrapheneOS, LineageOS, et al.
Firmware is included for 45 devices, but no one but the vendor/manufacturer can actually provide security updates for them, so they are largely just the last release.
Don't get me wrong, it's terrific that security patches are backported to such ancient versions of Android by those working on DivestOS and it's a great option for devices that aren't supported by GrapheneOS, LineageOS, et al.