If Orion is configured to block all pop-up windows (Settings → Websites → Pop-up Windows → 'Block'), trying to manually open an iframe in a new window via the context menu (right click frame → Open in New Window) does not work.
Since this a manual user-initiated action it should always work regardless of the pop-up setting – it's no different to right clicking a link and selecting "open in new tab".
Version 0.99.126.4.1-beta (WebKit 618.1.2)
Sonoma (14)