Emailed author
varthall01@gmail.com , see if will port to os3 , doubt it but if you never ask you never know.
He was just uploader. It was done by Friedens brothers, abandoned in half useful state (even its decent browser with few bugs), and what is marrier does not work on non FFS partitions and On latest OS 4.1 Final Update 1 - even in OS 4.1
So no, there will be no os3 versions. OS4 version includes a lot of Linux files unavail in OS, early versions asked even for special device mounted.
Laughable is that Friendens HQ still promises it will be upgraded from FF 4.0 to FF 19.0 engine
http://friedenhq.org/amiga/timberwolf/
Who wants to look at source mess, they have published it.
https://github.com/tfrieden/timberwolf