In the current state of SRFI 44, there is no way to declare what
equality
comparison function to use for bag elements, set elements, and
dictionary
keys.

I would like some way to specify what function be used to compare two
elements (i.e. the arguments to the function should be congruent with
EQ?)
when creating bags, sets, and dictionaries (in which case, keys would be
compared), and perhaps also some way to specify a comparison function in
all (or at least some) of the operations on bags, sets, and
dictionaries.