If you edit the poser_12 poser addon file - you should be able to stop Dson from being loaded.

you should find these lines in your poseraddon.py

for runtimePath in poser.Libraries():
    _loadAddons(runtimePath)

try something like this:

for runtimePath in poser.Libraries(): 
    if not runtimePath == "path to runtime containing Dson":
         _loadAddons(runtimePath)

Locked Out