It's possible to mod the mod system, to change that regular expression to something that would work better.
I wasn't very familiar with Godot syntax when I wrote that regular expression. I had to look up multi-line variables, and was not aware at the time that a dictionary with multiple values could be declared on a single line, and I couldn't even find an example of a static multi-dimensional array/dictionary and its declaration.
Regular expressions are... difficult to get right.
Having said that,
what is a regex tester and where can I find one?