We have recently added AMPHML animated ads export for Google Ads https://onlymega.com/amphtml-banner-maker/ and the only way to create animations is to use https://amp.dev/documentation/components/amp-animation component that controls CSS animations. GreenSock is not supported because no JavaScript is allowed in A4A.
For Google Ads Exits are not required because your banner will be placed in a special iframe with an overlay that will handle all mouse interactions and clicks using landing urls from Google Ads campaign.
BTW it's still possible to use normal html5 banners (150kb) and even hosted html5 banners with 2.5mb size limit (with google certified technical vendor like https://bannernow.com/ ).
