You aren't missing anything. Depending on how the motorcycle is acessorized, the weight bias may well be forwatd of the center of the lugs a bit, or back from the centerline depending again on what is on the motorcycle. An example would be Corbin Beetle bags and a backrest with no windshield and the bags loaded. The would bias the weight toward the rear. A full touring windshiled, lowers and acessory gages all add weight bias forward, especially with empty leather panniers (my situation).
When I stand my R3 on a steel plate vertically (thank goodness for the shop hoist), It's easy to rock the bike forward and aft but it wants to settle on the front wheel (lightly).
Any lift assist (or aid if you will), will only allow an unobstructed lift of the bike for maintenance/cleaning and depending on the weight bias, one the other, will be off the ground. You'd have to use a block of wood on the other jack leg to equalizr the front and rear but that much better than lifting solely by the cast aluminum sump plate because it applies no strain to the casting or the bottom of the motor ans no matter how the bike settles (front or rear wheel) it allows unobstructed access to the sump plugs, easier filter changes and for you clean freaks, the ability to clean the sump plate of road grime without laying on the floor, looking up, at an angle.
I need to add a little spice here and ask what the difference between the lugs on the Touring versus the Classic/Standard is or is it the OEM exhaust that protrudes into the lug space? Having no Touring available, I can't ascertain that.