Despite the fact that the Accept Hosted documentation says...

With any of the form integration methods, information specific to the customer can be passed back to the merchant’s server by embedding it in the continue/return URL or the cancel URL.

...so far I cannot figure out how, or even if, the continue/return URL provided in the token request is used in an iFrame integration. The request parameters documentation also says the continue/return URL is "optional" in iFrame integrations. Does it do anything at all?

I'm trying desperately to figure out how to get a few pieces merchant-defined information back out of the response, so that I can build out the correct receipt output, and I thought it would come from query string parameters added to the continue/return URL, but I'm starting to feel skeptical.

Thanks, Fritz