Finally got the SS ranking on Master mode in Tetris Effect
You need 150 lines clear and I think 175k points.
I played on starting speed M12 ( master mode is insanely fast the pieces don't even fall and are on the ground by default you have to keep moving and rotating the pieces so they don't lock into place long enough to make the board. I got 160 lines in this run and a score of 256k well above the treshold for SS ranking.
@coolboymew