Yeah, I know it's weird, but bear with me and just humor me for a while.
Most of you probably have seen the HT-Racing oil resevoir:
for some KTMs. Right?
The reasoning/desire behind these is to give a bike with relatively limited oil capacity (less than two liters) more oil capacity. The premise being that, all else being equal, more oil capacity generally means cooler oil, maybe less wear/contamination of the oil, and longer distances/times between oil changes. I don't think the reasoning or premise is flawed. Not sure that twice the oil would mean half the wear, or twice the distance/time between changes, but I do think it would be an improvement.
I do think there is room on the left side of the 70 degree engine for an oil reservoir, but it would increase the width of the engine, and it would be vulnerable when the bike is dropped. Such a thing might be incorporated into a skid plate, kind of like what one bash plate manufacturer did for water for rallye bikes (can't find which right now). Current capacity is 1.35 L (?) - so adding at least another liter would help.
If a person was so inclined, could they instead use the subframe for an oil tank and plumb that into the system?
Would the oil get too hot for the plastic subframe?
Would there be a better place to add at least a liter of oil?