Now I know more about how your system is setup (from other bug reports you have
submitted), I am going to change the severity of this report to wishlist.
That doesn't mean I don't understand your concerns, or think that they are not
important. However, booting Debian without initramfs to mount /usr has not been
officially supported for a number of releases (Jessie or even Wheezy, I
think). I regret this and wish it still was a possibility. But that decision has
been made and I see no realistic or practical way of Devuan going against it.
I know that will be disappointing to you. If you have practical ways you think
we can achieve it, by all means say.