To lower or not to lower???

You're only considering half of the travel. At the stock ride height there should be about 2.5" to the bump stop. The other 2.5" is before the UCA hits the upper bumpstop at full extension. I only have ~1" from the frame to the .375" tall bump stop on the LCA. I also use a taller bumpstop for the UCA, because otherwise the LCA drops off of the torsion bar adjuster at full extension.

Stock lower bump stops are 1.4" to 1.5" tall btw.