Issues that I hope to address soon with a future version:
1. With tall prints that use the full Z range of the printer, certain types of spools can potentially cause a problem near the top of the print. Most plastic and cardboard spools will rest securely on the roller, such that the spool will remain perpendicular to the roller during the print, even as the filament pulls on it one way or another as the toolhead moves left and right on the X axis. But narrow spools, or spools in with a narrow hub (like 3D Fuel), can twist off-axis just enough to make it possible for toolhead to collide with the edge of the spool during the top few layers of tall prints. I posted this note immediately upon discovering this issue (5/6/2024). I had a layer shift at the very top of a tall print using 3D Fuel filament with the narrow hub, and determined the toolhead/spool collision to be the cause.
2. The 2-finger handle section seems plenty strong, but is a bit thin at the very top. I plan to add more material to provide more confidence in the handle's ability to withstand any stresses during use.
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This remix adds a small, 2-finger handle, which does not extend beyond the profile of the original Z tower cap. This makes it impossible for the toolhead cable or PTFE tubing to get caught on the handle, which is a problem that has been reported with larger handles. It's not as comfortable a handle, but most people should have no problem using only 2 fingers to lift or reposition the A1 Mini.

Extra Hardware Required:
(7) M3 screws with 12mm thread length.
(2) Roller blade bearings (608 type 22 x 7mm with 8mm ID)
The original M3 screw on the front of the Z tower's factory cap is reused.

To install (see photos): Replace the factory Z tower cap with the Base part, using (3) M3 12mm screws, plus the original countersunk M3 screw for the front tab. Use (4) M3 12mm screws to screw the Upper part to the Base part. Attach bearings to the roller ends and set in place. Keep the original PTFE filament tube in place, clipped to the cable to provide support and strain relief to the cable. Install a new PTFE tube of 180mm (7") length to run the filament through. The cable clips from shiko work well for this. I would not suggest using the tighter version of the clips, because it seemed to compress the PTFE tubing enough to add friction to the filament passing through. 
https://makerworld.com/en/models/41020#profileId-41077

This spool holder is a remix of cprjared's A1 Mini Top Spool Mount 
https://makerworld.com/en/models/144910?from=search#profileId-157634

which is a remix of LwFactory's A1 mini handle.