Hi,
zoom contents (property applied to a group) partly leads to blurry displaying in safari (9.1) and chrome.
vector or pixelated stuff -> doesn’t seem to make a difference
Have a nice day 
Hans
Zoom translates to transform and I experienced that behaviour too but thats a Browser thing. Using Goggle Webdesigner I usually create my asset in the size of the biggest zoom-end-state and just start at for example 50% and then zoom to 100%. This should also work in Hype.
Hope this helps.
Another thing you might try… if you don’t want to have bigger symbols. Working with encapsulated groups try to use bigger assets inside a symbol/group and scale/zoom them down inside the group that will be zoomed up later. Let me know if that works if you try it.
thx, that seems to be a working method