Support AP Ratios

Riot, have you guys given up on ratios on utility spells like movement speed? I notice Bard has none. Is it because of the problems with champions like Lulu that basically made them better mages because ratios don't belong on support champions with low sources of income?

I'm curious if you guys have given thoughts to creative scaling. For example, a decreasing scaling that gives the first 50 AP a high ratio (~0.9 AP) that drops off to a very low scaling at 400+ (~0.4 AP) which averages out to a relatively low number (~0.5-0.6 AP). This could give supports a way to be competitive in utility but would be unattractive to mid laners wanting a strong scaling champion.