Engine oil leak

[5th_bike]

I changed the oil and oil filter in my 2005 GZ250 right after I had brought it home, because it was two years old. A few remarks and a question, after reading the above:

1) A GZ250 oil change is Messy, to put it mildly. At first, after removing the plug, the oil flows straight down in a thick beam, but in the trickle phase after that it goes sideways onto the left exhaust pipe. If unsufficiently removed, it will temporarily give a burning smell later on.

2) A GZ250 oil filter change is even Messier. (BTW the torque on the three little bolts of the oil filter cap I measured at 7 lbs/ft when unscrewing them). During removal of the cap, a big puddle of oil comes sploosh from underneath and all over the motor and parts underneath it, including the right exhaust pipe...

Then, the question: why should it be necessary to remove the oil sump cap (I assume =the part on the bottom that the drain plug is in the middle of) for an oil change ? I only removed the drain plug and let the oil leak out (moving the motor left and right gives a little extra old oil) - I didn't know the oil sump cap needs removal too, and for what. If it does, please let me know, if it doesn't, please just ignore, thank you.