With Global tick time scale set to 120 fps, as the mod works it slows down everything and speeds up the game to result in 120 fps play, or 144 fps, or 30, or whatever you please, however with GTTS set, what happens with actual craft times, and the game default UI, anything that mentions crafting time or items/s is affected by this, and since the game speed is sped up instead of just the objects themselves, actual craft time cant recognize this and it results in reporting that items/s are halved, so at 120 fps, you have to multiply the items/s by two to find out what you'd actually get, and the time it takes for something to craft or be consumed is doubled, meaning you have to do the math to halve it, to find out what your actually crafting and how fast the things will be. Now I know, there's probably no way to fix this, because the game can't be self aware of whether it's in twice the speed or not and adjust accordingly, but i feel there should be a compatibility addon of some sort that theoretically should allow this to work, whether it involves halving the reported craft times or something, I feel like there should be a way to fix this, but I'm no mod developer, I'm just going off of what I think is possible and it might not actually be, but I thought i should mention it anyways, as it makes planning out your factory just a tiny bit more confusing, most especially when the FPS is set to a factor that is not of 60, like 144, which i used to have my GTTS set to but then it got too confusing, but anyways hope this helps, and as a point of reference, the actual craft times mod im using since there are many is Actual Craft Time by osldgoth