Mitchell Smithey put the same compensator on my MSA with the A pedal slightly pulling up strings 3 and 6. I changed this to the F lever pulling up string 6 only as string 3 seemed OK and the return seemed a bit laggy on the A pedal. This works well for me and brings the AF combination into tune as was intended in the original rodding.
I have experienced the B pedal staying slightly sharp on string 6 on occasion as Calum describes, mainly when I go straight from an AF combination to an AB combination. If I slackened off the compensator rod this problem disappeared. I found that oiling the changer fixed the problem for a period of time and then I would have to lube the changer again to stop this happening. Probably needs done every couple of months though I haven't timed it exactly.
Recently I flushed the changer and re-lubed, not particularly to solve this problem but just as a routine maintenance measure, so far the problem has not resurfaced. My feeling is this is caused by the law of gunge rather than the laws of physics. I also recently bought a cover for my MSA to stop dust etc falling into the changer, if you compare my studio which rarely gets vacuumed, with the rest of my house which my wife takes care of, there is a considerable build up of dust over a short period of time. That same dust falling into the changer is bound to gunge up the finger mechanisms and very slight pulls such as from compensator rods are liable to suffer from sticky fingers, (if you'll forgive the expression!). So a little injection of oil when this problem starts sorts it for a while.
Just my humble opinion
