not sure what bike you have, but they did my rg w/o taking the tank off, just raised the back and tipped it forward.
That's interesting. But for us novices, who don't do it in our sleep every day, taking the tank off gives a better view and access, also reduces the risk of spoiling the tank!
interesting question,looking to do the same and will pull the tank and possably check the fuel filter while im in there. Also dont want to buy every possible tool that you might need if leaveing the tank on?