I’m not sure if you’re directing your comment at us or at Thunkable Staff but just to be clear, I’m a customer. I don’t have any affiliation with Thunkable beyond that.
I don’t know of any forums. There may be some. I just recently learned about the distance matrix API myself. As I looked into it, I decided I preferred to use the haversine formula for calculating distance. So I added that to my project and it seems to be working pretty well. It was several hours of work but this was really helpful: Calculate distance travelled - #15 by tatiang