There is a big issue with Grut's Haste Spores , although pretty fun to break combat with -->
https://youtu.be/rP_RqxfDbKkGlut also will eventually go back to camp on his own instead of giving you any option to "If you go further he will do that" option. This means when you teleport back to the myconid colony he will automatically be attacking the others if you agreed to help him, which is a rough fight that we only beat with the above glitch since we didnt know we should have rested before heading back.