This topic has been discussed extensively and brought up numerous times at this point since becoming a known/regular instance. I wanted to shed my insight on the subject after inspecting a P1P suffering a constant HMS: [Abnormal Motor-A resistance] error alarm 
every start up and print job… for months now.
Reading a lot about toothed pulley versus smoothed pulleys, doesn’t seem to be a permanent fix. I’ll side with BL on their comment based from a user stating they’ve found it to be more hurtful than helpful in the long term as why the decision for smooth pulleys was made.
Now I noticed a squeaky sound from the [Rear Right Side] - <Facing @ Rear panel> and seen the belt would rub ever so slightly against the lower flange of the pulleys. Noticing how the pulley tensioners work isn’t as easy as how [BL] makes it seem when providing their video on tensioning the belts.
•This is the [Left Rear Side] photo above.
- After an hour of tensioning again and again I finally was able to achieve the belt to ride in the middle but still shift near the top/bottom when all the way forward/back.
- This generated a smoother flow of the toolhead without a squeaky sound as well.
- I measured the gaps of the [Red Arrowed Regions] of the tensioner & pulley. They obviously are very different plus shift as machine warms up & ambient temps change with the belts
This is the [Right Rear Side] photo above.
•I’ll update with comparisons of prints post alignment & aligned
Basically of all the different topics on how to resolve this due to how the machine is laid out and functions, this will vary amongst every single printer will absolutely zero standard and that’s just the way it’ll be due to how it’s designed.
My theory’s on resolutions and remedy’s
• Bambu Labs changes design to incorporate a [Taller Rear Set of Pulleys] to accommodate the travel of the belt to prevent any rubbing
• I’m going to design a “adjustable wedge”
- People in the machining industry will know something called a [MITEE-BITE] which is used to hold blocks of material with extreme force and pressure utilizing simple force of a taper on taper design.
Basically it’ll be 1 piece but have 2 rear counterbore threaded holes that’ll [pull] by thread a tapered rectangle a little bigger than the gaps in length and as it tightens it’ll [spread] the distance between the tensioner. Having [2] allows you to dial the upper and lower easily to align the belt.
This would be best suited in aluminum but I’ll attempted in FDM testing some filaments. But I find this more practical when “tensioning” your belts and not using a simple shim since none of the gaps are equal. Plus it’ll be 1 tool for the job, in/out then call it good. 
Another tool I was thinking would be useful is an adjustable parallel, also uses a tapered slider that’s used between 2 surfaces.
This doesn’t solve for a permanent fix but merely a faster tool for belt tensioning. Honestly Bambu Labs should make this device or a device.
Let me know what you think
not sure how it even works as “semi-auto” tensioning…