Yes. And they vary; a couple years ago, I did one that required a minimum 2700 refund.
And overpaying estimated taxes results in a refund.
And these shops often pay extraordinarily well. PLUS tax prep fees, all the advance fees, and so on.
I've even done the ones where the MSC sends you a fake W-2, SS#, etc.
Once, the W-2 was for the business next door; the tax preparer said, hm, I've never seen you in there. I told him I worked in the "back room", in accounting, LOL. Then he asked why my employer's ID # on the W-2 was different from the other employees. I told him "Hmpf. I don't even know what that is. Maybe because I work for the home office? You want me to call 'em and ask?"
For me, sometimes, playing dumb is the most difficult part of the job.