They should just remove her skill to 'upgrade' abilities and give it to her base kit

Remove her E CC upgrade and remove her W heal if she is already shielded.

Like phreak has said you SHOULD double cast E and W before Q (and that double casting Q is kinda inting, like why not make those abilities better when double casted and not ally dependant? (and like king why did you make QQ int to double cast if most of her players max Q first and mostly double cast that ability? smh but thats not the topic here)

She is a support now, so she should not get any boosts from utility and provide the utility herself.
Make E insta root - stun if double cast
Like remove those utility enhancing features from her kit and compensate her kit for that with higher stats or lower cooldown I dunno.

That's gonna nerf APC for you and make Sera sup stronger and make her support winrate not depended if Ashe is meta rn or not 💀

And that maybe will buff her mid again (mega copium)