1) I'm fine with S.H.I.E.L.D. stumbling onto the formula, as long as it it not as effective as the one used on Steve Rodgers.  Having a formula that is on par with the one used on Steve Rodgers sort of defeats the purpose of rivial companies (like Roxxon, Oscorp, Hammer Industries) pursuing the "Superhuman Arms Race", as it did in the Ultimate Universe.

2) As long as it is not sudden.  This should be a long-term plan/plot.