@privateger There are so many ways this could be solved.
Set the cache to 5 min so it handles large bursts of requests.
Load a cached article and use JS to swap cached ads with dynamic ones.
Look at the user agent and use a cached version if it matches Mastodon (and other known scrapers), if you insist on dynamic ads without JS.
That took me 2 minutes of brainstorming, like come on.