is it ok to change the source scripts?

hi, i'm a new coder. just a thing about the built in scripts or whatever you call it. i was playing around with experimental light class, i wanted to be able to change how far my character emits light over time by a script and realised that most of the properties of Light2D class only has get method. so, i've made a set method for pointLightDistance property in Light2D class.

It works but, is this bad? or a thing that i should not do? just wanted to ask that.