I assume you're not acutally linking two digits of ELF version number
into the final binary? ELF version numbers are hard-bound: link
against libfoo.so.0.0, upgrade to libfoo.so.0.1, remove libfoo.so.0.0,
and then the linked binary fails to find libfoo.so.0.0.

At least, that's what happened when I did ld.elf_so integration on pmaxes.
I was told at the time that "that's how ELF is supposed to work".

The approved NetBSD procedure is to link against libfoo.so.0, and rely
on the NetBSD install make-target/tools to make symlinks from the
'latest" libfoo.0.x minor number, to the minorless libfoo.so.x.0.
(s/.so.0/so.X/g, for  X != 0)