Doesn't need to be so complicated and doesn't need to affect your Forward Flight.

If you are really interested in this from the perspective of scale heli appearance and practical flying then you could make a stabilizer that pivots, operated from a servo. The channel operating it is mixed with your Normal / Idle 1 / Idle 2 switch on your Tx.

For take off and hover using normal have the stabilizer at down, when you switch to Idle 1 for FF, have the stabilizer switched to its horizontal position. Depending on your Tx you could have the stabilizer servo operated slowly or put a servo slow device between the Rx and that servo.