Surely it’s possible to fix makepanda so that it will run a previously-built interrogate instead of the built interrogate. For instance, via an option like --interrogate c:/stbin/interrogate_x86.exe or something like that.
It does mean that someone would have to build a new interrogate by hand after any updates to interrogate itself, which might become a bit of a nuisance; but updates to interrogate are infrequent enough it may not be that bad.
David