Im a guy who has wheeled on both an Imperial (my own) and a neighbors. If you are doing aluminum, you CAN get thru it, but the extra time you spend wheeling will amaze you. And fustrate you. 18 ga Steel? forget it. You'll be collecting social security befre its done.
Theres many ways to move mountains and molehills. You could wheel your brains out for 2 weeks on a heavily crowned panel, or beat it with a mallet/slapper & sand bag to get a general shape, then wheel the walnuts out and planish it smooth. This takes 20 minutes. The stiffer the spine, the faster it will work. The less fustrating it becomes.