I think the fiddly work of modifying the thin plastic of the epson holders would end up being as difficult as having a made to spec holder printed.
Also I don’t own a v850 but the depth of focus on my v600 is deep enough that the micro adjustments of the better scanning holders are massive overkill. The reorientable inserts for adjusting depth included on the epson holders are more than good enough.
Also I don’t own a v850 but the depth of focus on my v600 is deep enough that the micro adjustments of the better scanning holders are massive overkill. The reorientable inserts for adjusting depth included on the epson holders are more than good enough.