Update 3/10/24:

Spool Weight
No change to spool adapter but based on feedback, on issues with very small/light spools like the 120mm ones, I've remixed and tested spool weight that sits inside the spools hole and adds some extra weight to prevent the spool from hopping on the forward AMS roller and getting stuck.  This isn't so much an  issue with the spool adapter, more then an issue with the AMS's design being prone to this issue which I've experience on larger spools as well without the adapter in use, but regardless, the weight should help.

V2.1 Update 2/20/24:

-Added small extension ‘arms’ forward of 120mm slot to limit side to side movement off the roller when using small/narrow spools.

-Additional reworking and shaving of roller slot side brackets to provide better fitment when two adapters are installed side-by-side.

V2 - Update 2/11/24

Reworked the model a bit to merge both 120mm and 160mm version into a single adjustable spool adapter that maintains the support system under the adapter, as well as my other improvements. Also integrated the Bambu Lab logo that gives it nice, finished look.

Based upon excellent work by @fredck_445523 and @BilliePalmer_544273.

I likes the improvements made here but had two problems. First one of the legs would repeatedly break off half way through printing, no matter what settings I adjusted. Second, I found that it didn't even end up fitting the spool size I needed as I have several 120mm spools of SUNLU PETG .25Kg that I wanted a better solution for then the giant wheel/spool adapter I'd previously tried. After a bit of tweaking, I feel I've both improved on the original design and have addressed the issue of the leg breaking off by adding an additional arched brace between both sides' legs, that keeps everything held together from the very beginning of print and eliminates all issues with the leg breaking off.