Definitely not... because there's no need to proxy all the requests just to be able to dynamically change the endpoint (or other details about how/if it accesse

Definitely not... because there's no need to proxy all the requests just to be able to dynamically change the endpoint (or other details about how/if it accesses the safe browsing endpoint). In aggregate, that's not insignificant traffic, so you wouldn't want to use your own resources to process it without a worthwhile reason.