I don't. The English version [https://en.wikipedia.org/wiki/Geigenwerk] suggests the a hurdy-gurdy wheel is in constant contact with strings, while the viola organista allows for a large number of strings to lower on to the wheel, so individual notes strings and notes are played.
This seems like he moved technology forward, no?
The hurdy-gurdy has 4 drone strings and 2 for melodies, so it's a rather similar concept to bagpipes with regards how it plays.