Noticed in a custom mission, started out low and slow, the trim gets set real funky. Nose was extremely trimmed up and she didn't want to accellerate. There's a neutral trim light in the cockpit of the Mig, top cluster of warning lights, it's the bottom right one, illuminates green only when trim is set to neutral. Hit Control-T to light it, felt like a ton was released and the nose dropped level real nicely. Been hitting it every mission now, makes a big difference to start from.
Don't know how the original trim position is set, but it was really different in that one mission, almost causes departure.