Offscreen rendering with QQuickRenderControl does not work with WebEngineView

I know that there's https://bugreports.qt.io/browse/QTBUG-50037 but that has been resolved 5 years ago and so much changed since then. Anyways, when I try to offscreen render a QML scene it works fine with the base QtQuick items, but for some reason it doesn't work with QtWebEngine items. I've used what's in attachment to see if I could see any result with WebEngineView but no dice and I can only see black in the revealed image, compared to other items which show up as expected. I know that in this version it could work with the offscreen platform per what https://bugreports.qt.io/browse/QTBUG-132682 describes. I've also tried to make the offscreen context current, I've arrived at the same square.