[1000mp] Is QSK with Mark Field possible ?

[F8DQL]

Hello,
I recently bought a FT-1000MP Mark V Field and I am disapointed by the 
AGC response time.
The receiver recovery time is too long, it is impossible to receive 
between my signals when operating QSK at 20 wpm or more.
Is there a way to correct that ?
I noticed that the receiver recovery time was a bit better with the AGC 
slow mode, but not really convincing.
Thanks for your help.