I have played this game for a long time, at one point you would just edit the files and be done with it, now the file will revert if you try to change mechanics that way, and if you use the built in constant modifier it reverts next time you launch the game. Changing the constants every time is super frustrating and wastes a lot of time when you have to do it every time you play the game.

Hmm, I've had the constants revert if I add or remove mods, or even click the "Apply" button on the mod screen. Other than those occasions the constants have remained as I set them. I haven't started a new game in for several weeks though.

No it will actually revert for me every time you launch the game even if you then load a save it will change all the values on the save. It is extremely frustrating.

check that the mods folder is write enabled, in fact make sure all the game folders are write enabled. The save files don't save the constants status if you change the constants the saves will use the new constants.