My external spools kept falling off the spool holder I printed a long time ago and jamming up and failing prints. So I decided to design a new external spool holder to pit onto my modular AMS wall mount system:

AMS wall mounts for 16" studs with optional built in storage Remixed by adriangarside - MakerWorld

Since I use the external spool pretty irregularly, I didn't see the point of printing a more involved ones with lots more pieces and bearings. When I was originally using the Bambu rear spool holder it worked just fine for me. So I remixed a more complicated model to take just the HSW attachment piece and modified it you so you can repurpose that mount.

Since the brass inserts are on the opposite side to the bolt, the model is designed to have the brass inserts press fit into place - you can use a vice or just put them on an M3 bolt and hammer them in gently (make sure you have them the right way round!). It's still a snug fit so you can still heat insert them with a soldering iron if you want. Then you'll need two M3x18 bolts to screw the Bambu spool hanger onto the model. M3x20 or longer will also work if you have space behind the honeycomb wall.