Hi all,
I’ve just put together a mod for my X1 to replace the extruder gear assembly with a drag knife to use it as a vinyl cutter, and I’ve put together a whole bunch of documentation on how to build it and use it: https://www.printables.com/model/560246-drag-knife-vinyl-cutter-adapter-for-bambu-x1/
It’s a pretty small print, and once you put it together, it takes only around 5 minutes to swap back and forth between 3D printer mode and vinyl cutter mode. For a laugh, I filmed and edited an instructional video in the style of the Bambu ones, too 
It’s working pretty reliably for me at this point. For instance, I’ve been able to use it to cut astonishingly good details on some vinyl that I plan to use as a mask for painting my bike – there are a few defects around start positions, but I think those might be fixable with some G-code generator changes.
For those of you who ask ‘why on earth did you do this?’, the short answer is ‘because I am pretty space constrained in my current residence, and if I can use my Bambu 3-axis CNC machine as a 2-axis CNC machine, rather than buying a separate Silhouette-brand 2-axis CNC machine, that would be meaningful in keeping the clutter down’. The long answer is ‘because I realized it was possible, and I have absolutely no self control’.
Hope this is useful for someone other than just me. And if not useful, I hope it’s amusing!