Yes. Absolutely it will work and it works very well.
We do advise the following precaution when doing so. The older curved jig does not have a base that it sits on, so it would be important that the hot kydex not fall off the edge of the jig and come into contact with the vacuum bed. Hot kydex could damage the vacuum bed. Use only a piece of Kydex sized so that it will not fall off the edge. Or, you can put a molding deck board underneath the Gen 1 curved jig. In which case, it would be advisable to drill holes all around the edge of the curved jig just like you would with any other mold. This will give you maximum airflow. The Gen 1 curved jig works best with a piece of rope, used to aid air evacuation, touching the gun.