Would it be possible to add in a option if storage is getting low? or is that not possible due to the modding API?

If that is possible I think it would be a neat feature to add

It is a nice idea, but Factorio does not allow to get information about the (host) OS oudside of the script-output folder. So reading free space on a harddisk is not possible as well.

Alternatively, you can setup an (external) monitor in your OS and still receive the warnings (just outside of Factorio though)

Alright, I feared as much thanks for the alternate Idea,

I forgot all about this the other day and couldn't figure out why I was so low on space when I finally checked this and I had 5TB (8TB disk) of data in the output folder

Love your work keep it up :=)

Haha, must be a nice timelapse cooking up!

And thank you for you kind words :)