I used pressure treated blocks of wood held in place with a lag bolt to see if I wanted to buy the lower StableLoads. Unlike you, I never had rattling pins - I kept the lock nut tight enough that almost didn't need the pins. After engaging the StableLoad wedge and pinning it, I would back off the StableLoad so there was pressure on the pin.
After two years with the lower StableLoads installed, I did not not see rubbing on the spring pack but did start to get corrosion on the wedges. I removed my lower StableLoads prior to selling my truck to the new owner that was going to use it for lighter trailer towing.
I considered making my own permanent wedges, but wanted something easy to engage/disengage. If I was not planning to use the truck unloaded, I would have a gone a similar route as above or still be using blocks of wood. Not all my solutions are as refined like the OP's.
I have used a number of the Energy Suspension products and feel they are good quality for the price. I even used them as taller upper overload pads before going to the stiffer Torklift product to reduce sag. They provided a better unloaded ride on rough roads where you need more suspension travel. I even mixed ES and TL products together to give me combinations not available by either company but ultimately went with the items that gave me the best loaded capacity and gave up on some of the unloaded comfort.