I have started a new (and typically insane) endeavor as a followup to my previous projects Waifs of the Boreas and Bi-Ethnic Characters of Hyperborea (both mentioned elsewhere on this forum). I'm going to produce 12 male and 12 female race kits, usable with Waifs of the Boreas, for every possible unique combination of the 21 interfertile human races of Hyperborea. I have already completed a 40 page document for all of the possible Amazon crosses (Amazon - Anglo-Saxon, Amazon - Carolingian Frank, etc.):
https://www.mediafire.com/file/o1w6f9clg2bha88/Bi-Ethnic_Waifs_of_the_Boreas_%2528Amazon_Crosses%2529.pdf/file
These race kits are not going to exactly conform with the procedures given in Bi-Ethnic Characters; far fewer of the crosses are going to yield "common" men (since I have to roll up all of the crosses anyway, I might as well tailor them a little more carefully to the appearances of the parent races). For example, among the Amazon crosses, only Amazon-Common yields a purely "common" offspring. Another quirk is that Amazon crosses with tall races yield tall women, but crosses with short races yield short men. And a few other little surprises.
My goal is to finish one set of crosses a month initially. Since I'm lazy (no, really) and not a complete glutton for punishment, I'm going to repeat the non-unique race kits (i.e., Anglo-Saxon - Amazon will be exactly the same as Amazon - Anglo-Saxon), so the number of new ones needed will dwindle with each successive race. The Yakuts won't need any new ones at all! But that's a long way away... Meanwhile, enjoy!