YVR to SHANGHAI to MNL to Shanghai to YVR

If those are your all stops, you are definitely eligible for 144 hour visa free transit in Shanghai twice. Of course, if one of your stops in Shanghai will be less than 24 hours long, then you will be eligible for 24 hour visa free transit. In any case, you are eligible for visa free transit and you don't need any kind of visa.

By the way, you should use correct terminology because it is not 144 hour transit visa, but 144 hour visa free transit. In other words, there is no visa at all.