I'll probably start a bunch of new arguments here, but there is more to consider than lane splitting as reasons to keep the bags close. I should probably go pull out my old Halliday and Resnick physics textbook, but the polar moment of hanging all that weight high and wide is probably the biggest influence on handling and the best reason for keeping the load tight. Think wire walkers with their long balance poles. Also, if you are truly "adventure riding", meaning loaded down over many miles of secondary or dirt roads, the further the load is placed from the centerline of the mounts means more cantilevered force on the mounting system. Unless adventure touring includes finding a welder every few days to fix the mount system, the closer the load is kept to the mount system or bike centerline, the more consistently reliable it will be.
After I wore out the original cases on my 89 R100GS, I bough a set of Givis off a crashed bike. Those lasted about a week, the handling difference between the Givis and stock bags was significant. I bought one of Jesse's first sets, and they were actually narrower than stock with about twice the load capacity. I had to re-weld the stock BMW brackets several times, but I never once had to reweld the Jesses. Al sent me a modified brace once no charge, but that was after my son had crashed the bike on the left bag (which did not keep the bag from functioning until we got home).
BTW, the beauty of the Jesses, in terms of in/liter, is that it is very possible to travel with everything inside the bags, tent, sleeping bags, etc. I love the Jesses in say Mexico, because I can leave the bike most any where without worrying about what's disappearing while I'm gone. Yea, I don't ride with GPS, XM or anything else either. Just my personal style, so we don't need a new thread on how dumb I am, but my idea of traveling doesn't include having to stay within sight distance of my bike or wear a backpack full of gear everywhere I go. The 90L Jesses give you the most options with all the right considerations.