It's a page rule, available at every plan level (I just checked the docs). Might be a problem if you've already used up your quota of page rules at a given level, but otherwise, no big deal.
Enterprise is largely about very high levels of bandwidth use, serving non-Webpage traffic, and all kinds of advanced networking features. It's also a hell of a jump in price from the $200/m top-tier "self-serve" plan (which is also the only self-serve plan with any SLA whatsoever, so, the only one any business beyond the "just testing the waters" phase should be on)
Right, the page rule is the setting, and AFAIK that's the same even on Enterprise. You're right that there's no check-box/toggle-slider to make it happen.
It's covered in what I'd consider to be one of a handful of docs pages that're must-read for most any level of usage of the service:
Enterprise is largely about very high levels of bandwidth use, serving non-Webpage traffic, and all kinds of advanced networking features. It's also a hell of a jump in price from the $200/m top-tier "self-serve" plan (which is also the only self-serve plan with any SLA whatsoever, so, the only one any business beyond the "just testing the waters" phase should be on)