If you're out for XPs, don't play MP games.
Best source viewed from the XP/time ratio is the CDP bonus (880 in 3 mins), closely followed by 18 hole tournaments, 470 in approx. 40 mins. Advantage of the latter: You can repeat it through the day.
In MPs you always have to wait for the others, and a 9 hole A/S brings 15 shots and 280 XPs in one hour.
Thus, please, enjoy the MP with some friends or other nice people instead of - sorry - whining for unseen XPs.
My 2 Pfennig