Sweet solution!
I’ll need to dig out exactly what I did, but I think I came up with an elasticity at 0 of around 20-25 in a vacuum. (so this gives me an idea of the underlying elasticity that exists from the nature of the comp with 10 equivalent competitors, but is probably inferior to your direct market probing) I think I generated a market of 10 competitors using the same lgb model built with 10 different seeds, and then playing around with the load/discount applied to individual competitors etc.