DO you think that this would affect the flight characteristics in a bad way if i put this on my heli?

How do you propose to so that? You'll need an airspeed sensor that drives a servo to slew the stabiliser, from 40 deg down at a hover to 0 degrees above 45 knots. If you think all that fuss is worth it, then go for it. I don't think there are any off the shelf systems, though.

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.

even more simplified

i saw a video of a scale UH-60 where they just left the stab hinged. in a hover it would just hang down, but in forward flight the airflow would "lift" the stab relative to air speed.