I followed a similar path after trying 4G thinking, hmmm, stiffer crosses provided great control, what other stiff crosses might do what 4G does but with more spin.
So I tried some of the stiff polys with lower friction from the TWU friction list (ie stiffness approaching 4G but lower friction). So far the best imo is Pro Hurricane Tour as a cross for gut mains. The others felt dead or very uncomfortable. Also, nothing that stiff has provided 4G's unique combination of comfort and control, at least in certain frames (open pattern and soft).
I'm trying an experiment with...get ready for this...bike handle bar Gel tape as a replacement grip, so if it works I might be able to use 4G in my Pure Storms.
Bike tape is MUCH thicker than racquet grips but far more cushioned. You couldn't use it without an OG but with one the only difference is a larger grip size. In this case TW only had 4-1/2" grips and my normal grip is 4-5/8. So I'm close to my normal grip in spite of the thickness.
If this works I'll probably buy future frames a size too small as so far it feels extremely comfortable.
Only on Talk Tennis can you find people who believe
that 10 feet of lead tape has no effect on a frame...