What inspired this wish list request?
As of JMP18 (based on JMP support comment) the excluded (unhidden) rows in fit model platform now show up as the letter 'e' with a very high transparency. The transparency for these points is too high so it's near impossible to actually see them - although I like the general feature. There is no known way to modify the transparency.
What is the improvement you would like to see?
Reduce the transparency of excluded points in the fit model platform.
Screenshot from JMP support:

Screenshot from my own analysis:

Why is this idea important?
Seems like potentially an easy change, since right now it's near impossible to visualize excluded data in a model. If we don't want it shown that's what the 'hide' status is for