Vlad
I'd be ready to wait. You could also do it by implementing a tiny "load RSS link" button in the crystal window that would only do discovery / load the link upon click and not in general (RSS is more of a niche feature now sadly).
If the URL of a youtube channel or video doesn't have the channel ID, as a user I would get the ID by opening the page -> Right Click -> View Page Source -> Ctrl + F: “ChannelID”, it shows up like this:
<meta itemprop="channelId" content="THE_CHANNEL_ID_HERE">
It would be great if it were possible for other sites as well. As for them, the RSS link is often linked in the page source like this
<link rel="alternate" type="application/rss+xml" title="RSS 2.0" href="https://www.something_something.com/feed.rss">
But I don't know how feasible it would be for you to process pages for RSS links in addition to serving search results, even if it's on demand only.