Maybe something else instead. e/os famously leaves the bootloader gaping open after the installation (looks like relocking is only supported on Fairphones), is very late to release anything (their most recent ROM is still based on AOSP 14!), inc.securty updates.
Doesn't sound like a serious project.
what else?
i'd rather have secure, stable and slow. i don't know about locking the bootloader (do you have a reference to that? i'd like to read up on it). but i don't care that their rom is always the most recent one.
what matters is that e/OS is the only rom i am aware of that combines usability with security. graphene OS doesn't count because it is only available on pixel phones and therefore very limited in applicability. others i don't know.