好了，问了一下移植的大神。
他说：
Not exactly sure to be honest. @
defconoi found it while digging through the art source. It has to do with art compiler flags and have the option of artd (which we don't have) art, art-full, art interpret only, and smart-art.
We were using plain art, the official preview was using interpret only so I decided to play around with it and it seems using smart-art is a bit smoother.
From what it looks like it has to do with compiling the apps ahead of time and when and how to do it.
I also turned the art profiler back on too
看来Google的大招还有好多。。