Seem like got a lot of friends out there facing the same issue like me.
Holding a foreigner passport but hope can stay in China for good or for travel. But China government alway change their policy. Maybe you can get 6 months visa in china but you gotta leave china every 30 or 60 days. This is really pain ass.
If we go to Hongkong to apply those visa, at least we need to stay there for couple days. The more faster also need 3-4 business days some will be 6-7 business days.
Finally, I got one company where in Harbin China can help me solve this issue.
I just need take my passport along and one picture. No additional documents need. They will help me apply 6 months visa without leaving china in this 6 months. If I need go out china. I just get another additional entry in my visa. They are helping me F change to L and Sometimes L to F. This will be handy for me to stay in china for my own good.
If friends out there wanna solve this issue. Can try look for this website visa.dimm2h.com