I really doubt anyone is going to revive those old legacy widgets. That style of widget is flawed and predates MVC-style design, you'll find it becomes very imp

I really doubt anyone is going to revive those old legacy widgets. That style of widget is flawed and predates MVC-style design, you'll find it becomes very impossible to present non-string data with that tree. Most applications now will want to show arbitrary widgets within the table, and for that they'll use the standard HTML/CSS. I would expect you can do something comparably fast by using a virtualized list in HTML, along with IndexedDB.