I just replaced the original nozzle cleaner with this one:
As a test, I did a 9 hour two-color print with many color changes. Result, no waste on the bed and no need to supervise; all the purges fell into the bin, behind the printer.
At this stage of modification, no other device in place, no reduction of the funnel and no mini brush leaving the funnel.
I will make other prints of several colors to test how it works over time.
For information:
Layer height 0.16
walls 3
filament flow ratio 0.9025
temperature range 220° 275°
nozzle temp first layer 255 others 252
Pei plate 70°