Exactly what effect on CG is caused by leaving the tail dolly on in flight?

I've seen many comments that this will "throw the CG off", risking safe control in a stall. But... I know gliders have successfully flown with the tail dolly in place. But I doubt that there's reason to panic, especially if one keeps the airspeed up.

And... some gliders are designed to carry tailfin ballast. For example, my Ventus can carry 2.0 L (kg), 4.4 lb of water in the tail. My tail dolly weighs 4.2 kg = 9.3 lb, only twice as much, and is a couple of feet forward of the tail ballast tank.

If I can lift the tail with the elevator during takeoff, I am going to be able to fly. So I can, to be safe in that circumstance, simply complete the takeoff, fly comfortably above stall speed, fly a normal pattern, and make a main-wheel landing to avoid the unknown control behavior close to stall and to avoid running the tailwheel caster down the runway at high speed, possibly shaking the thing to death.

Why not weigh one's dolly and do the weight-and-balance calculation? Then we will understand the consequences, if this happens to us, and will not panic.

Thanks for thinking about this.
Danl J