You may be correct that better targets are also be faster to market. We would also hope so: better targets might be more straightforward to validate in the lab and may enable smaller trial sizes, for instance. Timelines are still long and this doesn't alter my statement that the success or failure of our target selection strategy won't be known for some years.
Do you have any evidence for additivity not accounting for most heritability? I'll give one cite (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265475/). The fact that biology is very complex and non-linear is not inconsistent with most genetic effects being small and approximately additive.
We have never had a trait report on tongue curl, the 15-year-old blog post you linked to says it isn't a Mendelian trait, so I'm not sure where you were going with that. I can tell you that it is somewhat heritable but complex.
I was a team from Google that evaluated 23&Me's data and technology many years ago for a business deal. We already talked about this with Anne and she confirmed what I said above. It might have been before you were hired- but I'm pretty sure we talked about building a variant store and a transpose service? I stand by my statements (note: I work at a competitor of GSK and I know all about these deals). It's not correct that being better at picking targets doesn't shorten the timeline, either- at least in the opinion of the scientists at my company.
Additive models don't really account for most of the heritability of complex phenotypes. They're what have worked best and been published so far. Complex phenotypes are nonlinear because the generative processes in biology have feedback, homeostasis, enormous numbers of individual elements... etc...
By the way, does 23&Me still put tongue-twisting as a heritable trait on its reports? https://blog.23andme.com/articles/tackling-tongue-curling-th... It's not.