I usually burn a lot of supply in scenario 1 as i use all the R&D factories.
But i don't think it's a waste. It all dépends on the chain for each model.
I don't hesitate to use like 10 R&D factories for models like Zero, as it's not only about getting the A6m5 much earlier, but also the A6m8 (armored A6m5!) much much earlier. Same for the Tojo, as the IIc version is a real improvement compared to the IIa (armor+ slightly better armament) and it will be my main fighter type for most of my IJA squadrons, even when Frank (and his horrible service rating) will appear. So for this models i really burn supply to get them earlier because i feel it really worth it, and most of the factories will be kept on R&D when the first models of the chain appear.
And for the other important but later models with short chains (Frank, Georges, Judy, Sam, ect), i use 3 or 4 R&D factories. If i get them a few months earlier, it's fine, but the real interest is to have fully functionnal production factories from day 1 when the plane model becomes available .
I even use 1 R&D factory for future secondary plane models i plan to use (like transports, recon or night fighters) to get the production ready.
It's my main point for most of my R&D supply investment: the supply i have to use in expending the R&D factories won't have to be used in changing and expending again production factories from scratch + i get full production chains from day 1 for the new models.
< Message edited by Crazypantoufle -- 9/16/2015 10:16:37 AM >