I ended up building my own wings as well as the attachment point but later discovered that you can actually buy all the parts that are used with the festool UG extensions for fairly cheap as parts from festool directly this is all taken from festool's EKAT and to the best of my knowledge are the parts that are necessary to assemble one attachment point (ends up very similar to the fastcap but all festool parts)
the first column of numbers (2,3,4,5....) are just the diagram numbers and are not part of the item number, you can disregard these
Ug wing connection point w/hardware X 2 all parts and prices
2 228566 Square nut M6 1 $0.90
3 451630 Feather key 1 $2.59
4 479734 Auflageblech 1 $10.22
5 228541 Hexagon nut M6 1 $0.78
6 700472 Lug support 1 $6.12
7 486202 Rotary knob M6 1 $2.41
8 200684 Cheese head screw M6 x 12 1 $0.78
33 207813 Pressure spring 1 $0.78
I used small toggles as the attachment method, they work good but i think if i was to do it again i would buy these pieces and go this route
John