ok then, try the opposite approach. Load up your composer style and press the panel memory you want to change. Now call up the MSA and remember the sounds and volumes in R1, R2 and Left. Press the panel memory with your composer style again, and change the R1, R2 sounds and conductor status to the MSA ones. Then resave the panel memory. This way none of your composer accompaniment balances get changed and you only need to balance the volume of R1, R2 etc, but could be more complicated if eg Technichord or DSPs have been used in the new registration.

Alternatively in the panel memory filter there is an accomp and bass setting that will prevent the accomp volumes from changing but allow the right/left sound volumes to change from one panel memory to the next.

There is a single panel memory load that could be used, and also the other panel memory filters could be used to prevent changes you don't want taking effect, tempo etc, but the easiest method depends on exactly what parameters you want to keep and what you want to change from old to new style.