Electron supports multiple windows, but it ends up being annoying to do because each window runs in its own process. If your app has any kind of central state that's shared between windows, you end up copying data between processes frequently, which can be slow.

Rendering consistency is generally pretty good; I haven't run into any issues with that.

This bugs me to no end about Electron. The one module that existed to implement cross window / process communication is deprecated with no alternative. I haven't found a solution for multithreading in electron without killing the base process (which they explicitly say NOT to do compute in) or the rendering process (duh).

Web workers launched from the renderer work fairly well if you just need compute. I think I've also seen some apps add an additional BrowserWindow that's never displayed onscreen, although that will increase your memory overhead.

just ship everything with sqlite :) it'll be fine

This list is && not ||

Wouldn't it have been more concise then to just state that you "needed a framework that supported rendering to a window that isn't owned by the UI being rendered or created by the framework"? I guess now I'm even more confused about what Electron supports...

EDIT: Ok I see now, you listed your requirements and just stated that Electron doesn't satisfy them. The construct is confusing to me because the way it's worded seems to suggest Electron doesn't satisfy any of them, but I understand now.

Yea sorry for being unclear, I meant I need to do all those things. I have evaluated electron in the past and tried to hack the things I need unsuccessfully, but I don't keep up with it so I've edited my comment.