This is the big problem with Styles & why I never use them, plus I never want to do the same thing twice.
Every 2 image combination is unique & requires it's own timing & transition.
So I find it much easier to do everything myself rather than use a Style.
In PTE 11 you can create a Quick Style, which can be useful if you need to do the same thing to several images such as colour correction or resize.
If you really want to use Styles, such as the Ken Burns (which personally I find really distracting & nauseating if applied to all images) then do it before setting any of your individual timings or other adjustments. Or simply do it yourself in O&A to one Slide, then create a Quick Style & apply it to all the others as needed. This way they will keep their original timings.
Jill