I'm working on a cherry country hutch, the bottom case of which is made of raised panels (solid cherry), styles and rails. I've used spaceballs before, and I've read all the threads here about spaceballs. The plan I'm using does not call for spaceballs. I've already modified the panels by making them 1/8 inch smaller on all sides as the spaceball instructions specify. But the plan calls for a 1/4 inch by 1/4 inch groove in the styles and rails for the panels. Most of the threads here refer to a 1/4 " groove, but it's not clear whether they mean 1/4 wide or 1/4 deep grooves.) With a 1/4 deep groove, once you get the spaceballs in there (.26), there's no room for the panel's tongue. I don't think I should compress them because, if I do, there won't be anything left to compress should the wood swell next summer. Should I be making the grooves in the styles and rails 1/4" wide, but 3/8" deep? Something else?

Thanks in advance.