There is an updated pull request by q66 against master on the void-packages repository

https://github.com/void-ppc/void-packages repoconf-rework
https://github.com/void-linux/void-packages/pull/18661

xbps-src: per-architecture handling of repo confs
The new behavior is basically this:

1) Local repos are installed same as before.
2) Multilib configs are now handled only if they exist. They follow a naming system `repos-{local,remote}-ARCH-multilib.conf`.
3) Remote repo files follow naming `repos-remote-ARCH.conf`. If that does not exist, `repos-remote.conf` or `repos-remote-musl.conf` is used instead (fallback).
4) Cross follows the same behavior, just without multilib.

A patch file from https://github.com/void-linux/void-packages/pull/18661.patch is attached