There is an updated pull request by ericonr against master on the void-packages repository

https://github.com/ericonr/void-packages doas
https://github.com/void-linux/void-packages/pull/27958

opendoas: set permissions during do_install.
- setting permissions in a INSTALL script makes the program unusable
between it being unpacked and the INSTALL script actually being run; for
users with other long running post-install steps, e.g. DKMS modules,
this can be a long time where an administrative tool can't be used.

- furthermore, any interruption of the post-install steps or a power
failure will have a much higher probability of leaving the user with a
non suid executable than if it had been set at install time.

- making the binary permissions 4111 isn't necessary; the binary can be
retrieved in multiple manners, so this doesn't offer any protection (and
the binary would be "unprotected" anyway while INSTALL hasn't run yet).
opendoas's makefile can chmod the executable, so we just stop removing the
chmod line from its makefile.

@Duncaen 

A patch file from https://github.com/void-linux/void-packages/pull/27958.patch is attached