Rainer Weikusat:
...
> If moving the libraries was considered an acceptable solution, I'm
> willing to create bug reports (or whatever else would be suitable) with
> patches for the affected packages.
...

Bug report won't help since upstream Debian has decided to only support
merged /usr, thoose bugreports would only be rejected.

The only way to keep the non-merged /usr in devuan is to:

a, handle it yourself privately

b, recruit enought maintainers to maintain the packages within devuan

If any of you are not willing to become maintainers, then this
discussion is moot.

Regards,
/Karl Hammar