I don’t have a specific answer, but you could also look for tools that schedule reboots. If I remember correctly, a fresh boot has the same effects as lockdown mode. Fingerprint is not accepted, and the device contents remain encrypted until you unlock the first time.
If you want close to the bare minimum of software needed to run a system, and setup everything exactly as you like it, use arch.
If you want a preconfigured system that is performant, stable, secure, but still able to be customized to your liking, use Fedora.
If your scared of using a comand line for installation, use EndeavorOS.
I have used all 3 of these, in some capacity. I run my servers on Fedora Workstation, because it just works and comes with properly configured sepolicies out of the box. Arch has been the daily driver on my desktop/laptops for almost a decade now, because I often like to experiment with new programs and replacements for commonly used software, and the arch wiki is a wonderful. I tried EndeavorOS on an old PC to play YouTube videos/stream on my TV and it worked fine. I had to uninstall a handful of apps it came preloaded with, but that’s easy enough with an arch base. But IMO, now that the archinstall tool exists and is officially supported, there is actually no reason to use EndeavorOS unless you really don’t want to type a couple commands into a command line.