I actually built a second due to the wasted space in the first and needing additional larger board storage. Both are built with construction grade B/C plywood which unfortunately is usually warped to some extent but with these sizes can be worked with although a pain. Cost difference makes it worthwhile in my opinion. Guess I'm a bit tight. The second one, without wheels till tomorrow thanks to Amazon Prime, has the box and one divider. No smaller compartments. I just wanted something for the larger scraps and it has the same dimensions with exception that it fills out the entire base without and lip. So the box is 21x35 overall. This frees up the panel rack I built originally for 4x8 sheet goods with a bit of cutoff storage on the backside. This leaves my rack storage for long solid wood boards.
And for the record, I usually spend 4-6 hours at a time working on these projects, sometimes more, and always cleanup afterwards. It takes 10-15 minutes to vacuum using the central system (CV1800) with my shop vac adapters. Table saw surface and fence first, outfeed table, and any other surface used or with any amount of saw dust. Last is the floor. It just doesn't take that long. and I have very good dust collection system in play. The router table seldom needs any attention after use.