Thanks Michael, this deserves a longer response but a few thoughts on PTC (additional to the discussion in the original post): 

• I do agree with Jacob / Rethink's nudge that the alt proteins space needs to explore other theories of change - priorities 3 and to a certain extent 4 in this RFP rely less on this model being true (and more on what it would take for food manufacturers to adjust their formulations away from animal products).
• That said, I think there are perhaps two reasons one might underweight the review slightly:
  • Taste is underspecified IMO. The operationalization (to my memory) is mostly blind or informed hedonic tests on finished products. These are useful inputs but arguably underpowered for the question they're being asked to answer, and don't account for population heterogeneity in taste perception. A broader operationalization using analytical chemistry (eg. OAV profiles) suggests current products have made real progress but are nowhere near equivalence to target meats. So "taste-competitive PBM doesn't displace meat" is plausibly too strong a claim, using the evidence on current products.
  • On price, I'm less sure cross-price elasticity is the right lens: It's intuitively appealing, and the Rethink paper uses it sensibly, but I haven't found a historical food transition where x-price elasticity estimates were good forward predictors of how consumption shares would change with price changes. Chicken vs beef in the latter half of the 20th century is a plausible example - the x-price elasticity estimates tell a pretty confusing story, even though most people's intuitive read seems to be that chicken at least limited beef's growth. I think this reflects something about how the framework handles novelty and norm shifts at low penetration.
• Ultimately predicting shifts in tastes or technological change over long timescales is hard, and having good-tasting alt meat available seems like a decent bet to have placed under uncertainty.

Thanks, Fai - agree that this is interesting, and for those interested in this, I'd recommend looking at the fats section of the technical context note on new flavor active compounds. This isn't exactly what you're suggesting though - but a related idea.   
A caveat: Novel flavour compounds can also have off-target effects that we don't entirely understand - so this is an area where it may be worth treading with some caution. 

Thanks James - a few things to add to the discussion below:

On market failure: Alt protein R&D budgets have contracted significantly as the investment environment has tightened. Company incentives are much more geared toward extracting value from existing science than toward investing in long-horizon, early-technology-readiness-level research. Even where capital exists, investors aren't well-placed to identify the best marginal taste R&D - and their picks aren't always aligned with maximum reduction in animal suffering (e.g. beef flavour research vs. chicken flavour research).

On timelines: The R&D that maximises near-term sales for a single firm isn't the same as the R&D that's best for the market long-term - especially for pre-competitive science where you can't capture the full value. Eg. it makes much more commercial sense to do R&D on a new SKU than to invest in uncertain, harder-to-organise off-flavour work.

On $10M: Fair to be sceptical. The claim isn't that $10M fixes the whole problem - it's that (i) specific problems are neglected even relative to the few hundred million spent on alt protein R&D annually, and (ii) progress on the margin could drive more substitution away from the most numerous farmed animals.

On taste as a predictor of uptake: Genuinely hard to measure cleanly in a way that would satisfy most EAs. For what it's worth, on my model of taste - roughly (i) what does the analytical chemistry suggest about similarity to meat, and (ii) what does sensory panel data suggest - you do see something in the direction of more sales, though getting clean signal is hard given the difficulty of controlling for other uptake levers like distribution factors and portfolio depth.

Thanks David! Just noting that I agree that cost is important (my bad that this didn't come out clearer in the text above). If helpful, in the rubric for the RFP 3 out of 4 areas weigh cost at roughly 20-30% in our assessment (though it's of course up for debate whether that is the right number or it should be higher). Also, agree that plenty of bland products sell in volume - the problem is that even matching bland products often requires expensive patch jobs like flavour masks to cover off-notes in the base protein - and this often adds costs (hence the off-flavour track in the RFP)