I stupidly missed the part where you should choose gLIntercept (I grabbed both arcana's dropbox version and the latest from github) based on the application, not the operating system. CoH is a 32 bit app. The 64 bit gLIntercept wasn't responding at all.
Fixing that made it work. Sort of. It was hiccupping for a few seconds and putting Frame folders in the Paragon Chat directory (rather than in the COH folder, where I expected it to put them, and where the config and opengl32.dll are located). Those folders contained Images and Shaders subfolders, but no object. But at least it was responding.
Briefly. Then I realized that I'd forgotten to fix the plugin path in the gliconfig.ini, so it wasn't using Ogle at all. After fixing that, I can't get ParagonChat to start COH. All it says is "Failed to launch client".
If I deliberately break the plugin path, it starts opening CoH and creating folders again, but (obviously) not saving an object. I don't think it likes ogle. This happens with both the 0.5 version of gLIntercept and the current 1.3.3 version from github. I "reinstalled" ogle to no effect.
I tried to figure out how to pass -useTexEnvCombine to CoH. Unless Paragon Chat passes any unrecognized command line switches to the client (which it might, but I can't recall), I can't see any way to use that option. Either way, putting it in the PChat properties doesn't help.
I also tried putting the system's opengl32 into the game directory and setting GLSystemLib, but that didn't help either.
Unless the lack of -useTexEnvCombine is the problem, I'm stumped. Given that the DLL and config files are in the COH directory and the Frame folders are ending up in the Paragon Chat directory, maybe something is confused?