My friend is using 2 devices (2 chars) to open rooms for himself to reach 10k flags aps. Maniacally sitting there for hours sometimes, he already did 1k flags in 1 week (around 9k now) so it's all about if you are lazy or not. Up to you to run or not -> It has to be comptetitive.
Btw. you don't need 10k flags APS to get on Top Player Lb