(I hope this isn't too derailing... )

Seems like we have, broadly:

1) Lookup relative to/related to the include/module source search path
2) Lookup relative to linker search path/linker library location
3) Lookup relative to BMI search path/BMI location (which isn't
specified/standardized yet, so we'd have to standardize that in this
process - which I guess might be the reason it's suggested: in the hopes it
paves the way for some amount of BMI portability)

Perhaps a forth option?

4) Lookup relative to a new module config search path - perhaps this is (3)
with a different framing? (& could eventually grow to be a BMI search path
too - though I guess then we get into naming issues too, are BMIs then
stored alongside the module config file? Perhaps config files would be)