Basically what @cup_half_empty just replied, but I would to suggest something.
If you want any additional clarification, try reading through “Grr…More restrictions found on the stats screen” which is a thread about being unable to edit variables in the Stats Screen and other limitations. Dan Fabulich, the creator of ChoiceScript, has a lot of comments there regarding the issue.
Do note that the thread was made in July 2014 and the last post was in February 2019, so read through it with a pinch of salt because some details may be outdated.