Our current cardboard spool design has existed since 2015, providing a balance between waste and user experience. Having no spools sides, in our experience, does not give the highest quality user experience so we provide spools with sides (a previous blog on the subject).
Protopasta spool sides aren't overdesigned to use excessive material so there are outlying cases where the spool side condition affects the experience like when dropped. Assuming you don't drop your spool or put excessive force on the edge, they are typically durable enough to serve their purpose while minimizing environmental impact.
Edge style rollers can challenge edge durability and so can the Bambu AMS. You can remove the spool sides, but we don't recommend doing so. That said, if you drop your spool or just want to replace the cardboard spool side, you can do so. Here is an example fit to our 500g spool core size: https://www.thingiverse.com/thing:5775543
If you are using the AMS and willing to keep the lid partially opened, spool modification may not be required. You can leave the lid open, full or partially, or add a lid spacer if you like. Here is one of several lid spacer designs I've seen published: https://www.thingiverse.com/thing:5528378
If you want to be able to close the lid, you need to cut a couple mm from the outside of our spools. I've seen a design to do so here: https://www.thingiverse.com/thing:5489326
If you want to add a guard to avoid spool edge wear, we've seen many solutions. One is included in the above link. You'll want to size accordingly to fit whatever spool diameter you are working with.
Another option is to download my current preferred edge guard designed to make the spool larger. The lid will still need to be open and it relies on friction from an interference fit with the spool center opening.
What I like about this design so far is that no spool modification is required, it helps move full 1kg spools farther from interfering features, and does not block the corrugation for filament holding when not printing. If you try it out, please let me know if/how it works for you.
We have our own Bambu with AMS to test and build our own understanding, like anything, the user experience is varied. Some folks are fine working with our spools without modification, while others aren't. Initial spool condition, AMS settings, and material switches among other variables likely impact the experience. We're still working to build our understanding, but we'll keep searching how to get to best user experience when taking into consideration the new constraints that the Bambu AMS presents.
As we learn more, we'll work to evolve our approach for the future. And maybe there isn't a single fix that works for everyone because everyone has a different set of variables including different experiences and expectations, but building knowledge, awareness, and understanding for the pain points and sharing possible solutions seems like a good place to start.
Let us know what your experience is, how the above information serves you, and whether you have any suggestions to help improve the experience.
All our best,
Alex and the Protopasta Team