There is an updated pull request by Oreo639 against master on the void-packages repository

https://github.com/Oreo639/void-packages enable-befs
https://github.com/void-linux/void-packages/pull/13284

linux5.2: Enable befs suppport
This enables read only BeFS (officially called BFS) support for linux.
This is the filesystem used by Haiku OS.
If you want any changes, feel free to let me know ofc.

A patch file from https://github.com/void-linux/void-packages/pull/13284.patch is attached