Hi !
I have also bounce on tail ! and this on the both Spirit units I have. one on the Beam 450 SE and one on Protos 500.
On the Protos 500 I changed the servo (was a Futaba 9254 now is a KST MS 805 HV 760microS) and it behaves the same. On fast pirouette stops, it bounces. Change some parameters , as I read in manual and forum, the same sort of bounce, just sharper or softer, depends on values, but still the same bounce here. Until now I ignore it, because I thought is the tail servo, and everithing else work fine on Protos500. The rescue function has saved a cople of hundert Euros
her my .4ds file attached.