The short answer is no.
The long answer still admits that it's not a real word. You won't find it in Webster's. However, I still think it conveys meaning, and it's the best "word" that I could think of for the spirit of what I'm writing about. I mean it as the opposite of perfectionism...not someone who's seeking to be imperfect, but someone who accepts imperfection and is learning to thrive in imperfect environments. Clear as mud? Maybe a real-life example* will help.
Perfectionist: Can't start the dishes because there's only ten minutes which means there won't be enough time to mop the floor and scrub every surface. Since there's no time to do it right, why bother right now?
Imperfectionist. Realizes that 10 minutes spent loading the dishwasher and wiping off the counters will make a huge difference and just does it.
*Yes, both of these examples are from my own life. Sadly, I've picked the first more times than I care to admit.
Note to self: Always worth it to spend the ten minutes now. In fact, you usually won't even notice that the floor is not spotless or the microwave is still dirty inside if you just clean off the counters and load the dishwasher.