Great idea for a level-0 funnel! Just combining ancestries together is quite a simple and effective way to communicate the amalgamation! I’d probably tell my players to reroll if they got the same ancestry twice just to make sure they are getting the most fun of being a-live!
Something about the map that I’m not sure I understand is what exactly is the black blob and how it connects to other rooms. From the bridge, I thought it was some kind of underground rift, but it also connects to the kobold room where he observes from above, so I’m not really sure my interpretation is correct. Maybe a couple more words there could clear the confusion.