Recently I updated to v-ray 4.2.1 adn forest 6.2.2. I thought that IPR with forest will be very responsive in viewport.
I upload a short scene with few objects in forest. In this scene if I turn off forest i have above 100FPS, but when turned on it's below 10FPS and can edit anything.
Can you look at it?https://we.tl/t-WvYmUeLpUv
Max 2014, Win 10.