Setting the number of times a timeline should loop is definitely a cool idea and something we will consider for a future version.
Here is a javascript approach to loop the Main Timeline 4 times:
banner-loop.hype.zip (11.0 KB) .
If you prefer not to use javascript you could either copy/paste the animations 3 times or add a second timeline which is responsible for looping the Main Timeline. This timeline would simply have two actions that restart the main timeline and pause the current timeline. Then at the end of the Main Timeline continue this loop timeline.
banner-loop-no-javascript.hype.zip (11.5 KB)