I’ve gotten the wedge kits in the past only to discover I have no use for them. I’m not an AIWB guy, so they just don’t do much for me. I have two of the old Xiphos models, one for a Staccato C and the other for a G48. I use them both as a strong side holster carry and it really works well. Only “add on” I got with the holsters are the metal discreet carry clips.
Once you shoot the 4.0C, you need to let us know how it does. I really love mine!