Question about cheat engine

I was wondering if it is *relatively* safe to use the speed option of cheat engine on a bot like Grimoire or LeBot

I don't see why not, all the speed up option does is make you faster, you are running the exact same speed on everyone elses screen but you seem to be teleporting almost. Ever notice how you enter the same cell as someone and when you transition to the next cell they are already at the end and you've just entered, they are using the speed hack.