Im waiting since June a windshield for 2017 subaru forester with eyesigh, they said still on back order. Do the aftermarket windshield work well ?

Any car newer then 2012 I'd stick to the dealership. Best bet.

Unless it's a Subaru authorized replacement part, I wouldn't risk it. It would have to be made to manufacturer's specifications to accommodate for the eyesight system to ensure maximum reliability and safety. There's no guarantee an after-market windshield would be covered under Subaru's warranty if something were to go wrong. Always stick with OEM if you and your families life and safety depend on it.

No. Your windshield has built in heater elements for your wiper blades and up by the eyesight system is a special glass. People have tried using aftermarket windshields to find out it was wrong.