I put a shelf comprised of 2 2X6s under my Powermatic, and have stored my tool rests and chucks on it, and a bin containing jam/friction chucks. I had some chunks of wood that lived there and never had anything vibrate off. Recently, I put a rectangular box with my Oneway coring set up in it on the shelf in place of the jam/friction chucks. Can you say MASS!
The coring box hangs over the edge of the 2X6s a little in front and more in back. The box is immediately under the spindle/blank, but the places I need to get closest to the lathe when turning are toward the headstock and tailward, so it doesn't get in the way.
Before, I would sweep shavings from behind the lathe, under the shelf, and then shovel them up and out. The shelf itself catches a little debris which isn't hard to brush off with my hand. With the box 'o coring in place I have to sweep shavings off the top with my hand at cleanup time, and then do as previously. Neither of these processes is especially onerous. I have much more trouble cleaning up in the corner where live miscellaneous chunks of wood that didn't get turned when planned, right next to the bandsaw. Now that's a problem area, but there's not one under the lathe.