Robert
With regard to the multi-move mobiltiy calculation, I think we can ignore
levelling effects at the M2 etc level as well--levelling effect can't be
calculated on a per piece basis at all. For example, in FIDE Chess, the
levelling effect brings the queen's value down--but add a Queen to
Betza's Tripunch Chess and the levelling effect brings its value up!
I think the correct way to allow for the levelling effect is to calculate
all piece values ignoring it, then correct each piece value by an equation
which compares the uncorrected value to the per piece average (or perhaps
weighed average) value of the opponent's army. So the practical value of
a piece depends on what game it is in.