Soraka's healing spikes at lvl 9, with W maxed at a 2s cd, so she can get 2 Ws off of 1 Q hit.

Last year I thought with enough cdr, could you get 3? Pressing W during Q is much better for Soraka so you don't kill yourself (in game).

Unfortunately I've never done it in an actual game. You need something like 70 ability haste, and I'm not even sure how the cast time works and in general haste doesn't seem like the best stat for Soraka unless you're constantly able to hit Q. And most importantly if it's 40 minutes into the game you spend most of your time in close situations on Soraka running away; not standing there and perfectly ordering abilities.

Still, maybe one day!