Save the outputted css to the database

Problem/Motivation

I’ve noticed that if i add javascript then it's stripped from the resulting css which is great because that's what i want, but when i check the value saved to the database it still has the javascript which i don't want because I'm thinking about having the data for this css field sent through a json api call and I’d like to avoid having js in there.

How or where can i update the this modules code so that the processed css is what’s saved in the database? Would this be feasible or would i need to "patch" the module / make the change in my own custom module, if that's the case how would i go about it?

Steps to reproduce

Use module as normal.