Playing the treble viol and the violin, I came to notice an interesting fact. There wouldn’t be any musical reasons not holding the (baroque) violin bow at the frog.
In the late Renaissance period, people use the same bow for violins and treble viols.  I guess violinists might use the bow which treble violists played. As you know, violist does not hold the bow at the frog; they hold the root part of the bow. So the hairs of a root part are usually a little oily and dirty by the violist hand. There was no choice for violinists to hold the frog because the violinist could not make any sound at a root part. In modern days, the viol has its professional players and the violin has the same. Therefore, it is hard to imagine such confused situation might happen. I think it could happen.
The little dirty root hairs is not clear in the below picture

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