Add a Firmware function to pause the print and move head to front of printer and wait for a resume command. This permits access for manual nozzle cleaning mid-print.
The pause function moves the head to the rear and runs the nozzle across the roller and waits, but the roller does not clean the nozzle body, only the nozzle tip, and this often makes matters worse.
That would be an awesome feature especially for printing PETG as this material loves to form blobs at the side of the nozzle and then release it with the utmost precision on the very part of the print where it will cause the most damage. 
I use pause and then a long spatula to dislodge the filament from the nozzle.
Yes, this would be a good feature to have for sure 
It is possible to pause the print, move head to front, manual clean and resume print.
Not sure if bed can be lowered, during pause and resume.
It would just be nice if there was a one-button feature to do this.
I have lowered the bed before and when I hit resume everything moved back without issue.
Just add a G29.1 Z0.03 to your filament startup code, if it still gathers wisps, raise by .01 repeat.
Get this too, very reason I made it was petg wisp-prevention
Bambu Nozzle Wiper by Kungpaoshizi - Thingiverse