The common complaint I here with BC's is the rear end is terrible, you see the same complaint often with them for both 240 and 7/900 series
https://forums.turbobricks.com/showthread.php?t=354642
the reason is the wheel rate ends up with the rear being nearly double the stiffness of the front, the opposite of what you want for driving
I suspect but can not confirm that perhaps short GAZ dampers were used with 40mm lowering springs where they would need to be full length. Otherwise could simply be the dampening adjuster were just not set in the right kind of area