Currently, I'm planning to rebuild cinnamon-settings, to adjust the DPI settings for y hidpi display (cinnamon overrides manually-configured xorg, so I have little choice).
My plan is to grab the source, via git and xbps-src, starting with the instructions found here: https://github.com/voidlinux/void-packages
I imagine I won't need to perform any additional configuration, as I'm starting with a Void source package, and simply editing a line or two of C code, then building and installing.

Given the instructions at the aforementioned page, I ought to be able to simply edit the appropriate .c file in the package, then do the following:

$ ./xbps-src pkg cinnamon-settings
$ xbps-install --repository=/path/to/hostdir/binpkgs/..

That looks deceptively simple. Is there anything I'm missing?