My suggestions. Make the SAS-2 vernier pod th? true maneuvering liquid fuel engine with thrust vectoring. Add thrust vectoring to the Omnipotent Bertha - as it was with its real prototype, which actually consisted of many independent engines, and the deviation of the thrust vector was achieved by the difference in thrusts of opposite engines. Interchange characteristics of the Twin Bertha and the Large Bertha - just because the Twin Bertha looks more powerful. Remove thrust vectoring from the RMA-3 - it only interferes with the orbital maneuvering. Make the longer versions of the TK-421 decoupler, so they can cover engines above them.