Since update 2.108.001 Pose Editor allows you to load almost every thriXXX internal pose.
To start editing a thriXXX Pose, just click on the New button on the top of the left panel. A window with all available Poses will appear, select one and press ok and you are good to go!
Dual poses that have an anal/vaginal or femdom switch available in the FreeMode, will show up multiple times in the dialog, offering to start off from the 3 types.
There are some drawbacks, though, which are not solvable at the time of writing:
There are several reasons for that, the main one is, that all internal poses have not been made with the Pose Editor, but much earlier in the update cycle.