I would remove or nerf the crit from the Q, never been fan of the one shot build anyway and in my opinion on-hit is just better in higher MMR than crit because of all the Zhonya's and Stopwatch in the game so maybe balance him around that. I really hope you don't screw him up in Plat+ MMR.
Edit: Thank you for giving some context
crits a somewhat fake lever, since the crit build goes rageblade second and the lethality build goes crit second. AS tie in is more likely target (CD Refund on attack) if we act on the Q specifically