ephemeregames/searchify — comment on commit cc07c9fc9b5d40a92c7c4d0d0a4ccdec0827d34d
File:  line 0
By ephemeregames:

For polymorphic associations.

Example:
Model: C
Polymorphic owners: A, B

Search for Cs of owner A but redirect to C... of?
So IMO, if you search a scoped collection, you should be redirected to the scoped resource.