I like to make my own holster wedges so I can tailor them to my specific reality. I use minicell foam, a crosslink polyethylene material that is very durable and skin soft. I've been using the stuff for many years carving kayak and canoe seats and outfitting. I've a large box of scraps in the workshop which become holster wedges and other creations that improve the quality of life
I prefer to glue my wedges directly to the kydex using contact cement (Weldwood solvent based). Its proven to be a very durable method and can be removed with trace if desired.
This is an example of what most of my wedges look like:
I'm a 6'-2" slim fellow and this wedge works great for me. Tucks the handgun nicely. It tapers top to bottom and right to left with a soft roll. An additional benefit of a wedge is heat reduction during activity. The holster to body area gets a bit of ventilation which is definitely noticeable when hiking or paddling my canoe.