I used to plan to simply avoid the bg music problem in PG build by storing the starting time and bgmusic lenght, and stop-start when it ends.
But it's not a good way... in long term we could just hope that CocoonJS will make our games perfectly deploy existing C2 projects to android and iOS.
There is an alternative, AppMobi's direct canvas, but I found one main problem about it in several minutes: it have a bad version handlign, what makes updates deadly hard...