Hi
Sometimes I undergo the same issue, I use to make scenes, VNGE and so, I can tell, Graphic Mode is a RAM GPU eater. Sometimes I use to Disable the main light of the map, as I show in this picture, it helps a lot.
Have in mind that some plugins can affect the performance of the game, when I upgrade from fresh, zero, the game runs smooth, but when I add some plugins and mods, it seems to be slow at some points.
I got a Potato PC and a 4G Graphic card and works fine to me but yes, I remember when I ran Studio in BR8 it used to be more fluid