Any time you touch the height of the bike you are tampering with the work pf people who are paid (and know more than us) to design and engineer the suspension for the bike, some bikes usually high end sport bikes have some adjustment worked into these calculations but most bikes like us common people ride do not, the easiest and safest way to raise or lower a bike is through seat choice this way the suspension is not touched.
Few little tit bits that are conveniently left out when talking about height, raise to much then you should (if doing it correctly) also extend the side stand as is if lowering you should shorten the side stand, if raising or lowering the rear this tampers with the front end suspension as it was not designed for that new height.
Raise the ride height and you jack up the rear, this makes the front tyre work harder and allows the bike to turn quicker, the trade off is a loss of stability.
Lower the ride height and you do the opposite dropping the rear of the bike reduces the load on the front tyre.
Now why do we even have to mess with the suspension, most bikes are designed around a 180# 5'-6' to 5'-10" person now as the height might be a common factor that weight is effed up I have seen a lot of lets say heavy boys on bikes.
Stay stock height mess with the seat to go up or down.
Now getting back to your original question
I had two local MC shops try and swap out my progressive springs with no luck I ended up sending them back to progressive and they swapped them for a small charge.
