I have a complex model and many tabs with materials in the Slate Material Editor. If I use the compact material editor there is no problem. But when the Slate material editor is open, selecting objects in the viewport is slow (a lag of 2-4 seconds) between each selected objects. The viewport performance itself is great though, so that is not the problem. What could be causing this? I tested in 3dsmax 2018 and 2019.`