You will be surprised, hot oil is going to expand
Combine that with hard riding, the oil cannot find its way back to the oil pan fast enough and the head breathers are working as hard as they can
IMO you should NOT have oil laying in the bottom of your air filter housing, if that is the case can you imagine how much oil is getting in thru the throttle plate?
I have rode the snot out of a 15 and now my 17 Freewheeler, i keep the oil a bit more than 1/2 way up the stick and it does NOT puke oil JMO
Good Luck and happy riding your Trike
Check your oil level after a ride, how full or over full is it?
1/2 way up the stick cold is where my 17 oil is supposed to be, when hot it will be closer to the full mark