> As a rule of thumb, I find it's best to avoid one-shots (or "specials").
Absolutely, and I would never suggest that. However, it's not just RG that has this problem, right? If I understand correctly, isn't it every single customer who believed your advertising and followed your suggested strategy to use single-threaded Rails, and doesn't want to switch?
So it's not about short or medium term; it's about letting customers take the latency hit (as you note), in order to get the scaling properties that they already paid for.