That's a good way to put it. I'm glad this thread popped back up. I pulled this book out after not seeing it in about 15 years. I no longer keep a kit in my office, but I do keep my Prologix Blue Lighting pad on a stand under my desk for when I feel like taking a break.
There's also no law that says you can't elaborate on the etudes and use them as inspiration to create your own stuff. Ultimately what all material should come down to IMO, especially for a kit player and extra-especially for a jazzer.
There is a procedure if we want things to actually come out in our playing spontaneously.