I agree with the crawl. Every room is different, and though corner loading can work, it is not a guarantee in every room. Using the crawl can help you find the best places, acoustically, where your subs will be able to perform at their best.
In my room, the one corner I had available just created a very boomy and muddy mess of the bass. The crawl revealed my sidewalls to be very friendly homes indeed, and without much fuss was able to dial in pretty good measurements. When I get to spend more time with REW, I’m certain I can smooth everything out even more.