its mostly cosmetic. You arent going ot hurt anything but resale value by keeping it that way as long as you keep your oil up. Its about 400ml from the lower fill line to the top fill line with the bike upright and many here have taken to intentionally overfilling significantly past the viewing window altogether. If you arent sure of your oil consumption Id suggest you either
A - top it off to the top fill line as suggested by suzuki (bike verticle)and check your oil level every 50mi until you get a general idea how much you're going to lose over a given distance and make sure you keep it between the lower and upper fill line.
B - leave it on the sidestand and fill until you just barely see oil in the bottom of the viewing window. After 50 mi top it off until you see oil again just barely in the bottom of the viewing window, or after 50 mi heave it verticle and take a quick standing glance as to whether or not your window is completely black. if you can see the line of oil in the window, top it off.

Thanks for the feedback. Looks like the sun will be out some later today and it's off we go.
Ordered some of the bits mentioned and a date will be set for pulling things apart.
Thump on!