Sure, the odd RPC style HTTP call is fine - not everything is cleanly modelled as a resource. But the lack of a clean way to make GET requests with a more complex request payload is simply a wart/shortcoming in the HTTP protocol IMO, and one that’s very correctable. Sucks to have to abandon RESTfulness even when I have a very “clean fit for the resource model” call to make, but the request body is too complex/large for HTTP query params.