Strident is what happens when you go from soothing quarter-comma to harsh Pythagorean and keep going in the same direction. You could use this scale to emphasize the different sound of a medieval piece. Your harp was set up to play in 12-equal. So to stay in quarter-comma, you'd have to adjust the lever to sharpen the note by 24.5 cents less that 100, or 75.5 cents. In general, whatever the amount by which our fifth differs from 700 cents, we'd have to set the levers to have seven times that much correction from 100 cents.
Harps are too difficult to adjust.
Now, if you have a pedal steel to play with, THAT would be feasible. Let me know how it works out - Zeke Hoskin.