With not having had too much reading through the discussion thread,
and with the risk of repeating something old:

Does the Term "Vorsetzer" mean anything to you guys?  ;-)

greetings by(e) InK - Ingmar Krause

P.S.: I did use this Vorsetzer method for normal 88-keyless rolls
and it works fine -- and you do have the dynamics, too.

 [ Instead of playing a normal piano, the Vorsetzer (push-up player)
 [ pushes the keys of a velocity-sensing electronic keyboard with
 [ MIDI output.  -- Robbie