[API] Minor keys parallel or relative for best results?

I was playing around with the API but got some sus results when using minor keys expressed as b1, b2, etc… For example, there is a single suggestion for the progression i III when expressed as b1,b3… which is i III i iv i, kind of lame. Even more shockingly, b2,b5 does not suggest b1 but b2 again, and b2,5 suggests I (major), and b2,57 suggests nothing at all. What.

I’m wondering if maybe it’s best to express a minor key using its relative major key - for i I could instead type 6 rather than b1? My concern would be that then this would not understand the concept of a key center and would gravitate to a lot of V,Is, which would be a lot of VII,IIIs in minor and throw off the tonality completely.