bored marketeer Ortho-k would probably work although I believe it can be painful. If you are now outside of the initial limits but within the renewal limits then get ortho-k until you have a low enough prescription to pass the initial then let your eyes return to their normal state and you should be good for renewal.
As for having a diopter limit in the first place well that is just plain and simple bad science. The diopter is not a measure of how well you are seeing it is the strength of your lenses. It's only function is to make sure that your optician and the guy who makes your glasses are on the same page.
My uncorrected vision is 20/50 which is pretty good, I can get around without my glasses or contacts if I have to although I choose not to. My prescription is -2.75 in each eye. I have a friend who has uncorrected vision of 20/200 he is unable to function without his specs, his prescrition is -1.75 in each eye. Although in general the worse your eyesight the stronger the lens this is not true in all cases and if you can be corrected to 20/20 nothing should stand in your way of becoming a pilot.
The FAA used to require a waiver if uncorrected vision was worse than a certain level 20/200 I think was the cut off, everybody who asked for this waiver got it and after a long number of years where the accident statistics of these waivered airmen exactly matched their unwaivered counterparts and their were no accidents where poor eyesight was listed as a causal factor, the FAA dropped the requirement for a waiver. Now all you need is 20/20 with or without correction. A very practical and reasonable bunch the yanks are.