I think you use wax foundation which may not be stiff enough for my assembly technique.
I have been using double wax coated black plastic foundation and I found that assembling the frames with the foundation in place helps me get it all square and completely assembled in one go without a frame assembly jig.
I put the top bars on the table upside down, put glue on the side bars, push them on, put the foundation into the groove of the bottom bar and press this into the top bar-side bar assembly. I push the frames one side or the other to make sure everything is square and then put a 1/4” x 1.5” SS staple in each corner. I can do 10 frames in 5 minutes this way. Then put them between my basement rafters to dry, although, they are secure enough with the staples to use right away.
I’m sure that everyone has their own method but this has been the fastest way for me.