A bit cryptic, but my interpretation of this is that Resulting System Scaling ("the static text") is equal to Staff Height / 96 x Scale System (the tip is essential).Set the staff height, then apply a percentage to the value. The static text is the cumulative effect for all staves in the score.
Tip: The absolute staff height is 96 EVPUs (.3333 inches or .8467 cm).
I guess I wonder why they chose this way to specify 85% in the default document:
instead of this way:
(To me, anyway, it seems more intuitive to fix Staff Height at 96 and vary the percentage.)
Or, when Finale was first born, did they have a printed piece of music thought to have a good staff size, and so measured it, converted to EVPUs, and entered 82, which results in 85%? Is there a Finale Historian?
I'll admit that on a few occasions, desiring to match the staff size to some scanned old edition in order to make a patch with a paint program, I've just blundered along changing Staff Height by trial and error until they matched (somewhat laborious with the writing of graphics files for each trial) . If I had known, I could have converted DPI to EVPUs and got it right the first time.