When pasting in a youtube link containing an “&list=” part of the URL, it should show the linked video (i.e. the one specified by “v=”) first before all others.
Even more important when “list=WL”, as watch2gether does not have access to my personal watch later list, and thus completely breaks trying to load it.
I think a fix would be to load the first entry in the search results as if “list=” is completely gone, and then append on a second search with the “list=” parameter added back in. This might give duplicate entries if you pick a video early on in the playlist, but I think the trade-off is worth it.