Can you fit a Shimano Ultegra R8000 11 Speed Rear Derailleur Medium Cage To a ten speed cassette ?

[silver00]

I understand that r8000 cassette is 11sp . The smallest cog can be loosened. Can I 'lock' the cassette at 10 speeds???? And using cable length, and max, min screws on the r8000 derr to shift 10 instead of 11???? Up top, I'd shift to 10th gear (hardest gear and try to limit shifts using the max/min screws).
(My frame can accomodate 11s, but at lowest 11th gear, the chain runs against the tube, opposite the chain stay.)

 

[C R]

I understand that r8000 cassette is 11sp . The smallest cog can be loosened. Can I 'lock' the cassette at 10 speeds???? And using cable length, and max, min screws on the r8000 derr to shift 10 instead of 11???? Up top, I'd shift to 10th gear (hardest gear and try to limit shifts using the max/min screws).
(My frame can accomodate 11s, but at lowest 11th gear, the chain runs against the tube, opposite the chain stay.)

You can lock the smallest cog out, ie, hold the derailleur at the second smallest with the h limit screw. You will need the smallest cog in place for the locking ring to catch in the serrations afaict.