Use any spool holder with "UM2 connector" with this. Sits in the middle of the UM2(+) side panel. Tested with PLA, easily carries 2kg XL spools. Other materials might bend more. Can be fixed with the case screw on top, but not necessary.
Split in two parts to fit the build plate. Screw the two pieces together, with 2x 10mm M3 screws and 2 M3 nuts. Careful that the screws to not stick out on the back side, they might scratch the UM side panel. Eventually use a file to shorten them 0.5mm.
Note the design is made for 0.4mm nozzle and for tight fit. Printing with 0.8mm nozzle might result in much tighter fit or even not fit of the top hanger or the UM connector.
I am currently using two of them, one on each side panel, to feed my new Bondtech feeders. See photos.
PLA, 0,4mm nozzle, 0.2mm layers or less, 3-4 perimeters, 30-35% infill, top/bottom 1,5mm, 50-60mm/s print speed.