I know you're working on all-SMT versions of your OPA designs, but why not use SMT elcaps with enlarged solderpads, so you can solder them by wetting the pad that extends outside of the elcap pins? Cheaper, no (or less) microphonics, higher capacities available for improved CMRR and lower low-end noise, audio-grade versions available if that means anything to you, no cracking issues... Maybe I'm missing something, but could you explain your rationale for using MLCCs?
Btw, did you check your builds for microphonics?
Jan
