Flats do help with ‘finger noise’ and muting, but they don’t solve for it.
I noticed when I started playing that I gravitated towards flats for this very reason.
But, I wanted some of the brighter rounds tones too.
Over time your technique simply has to get (and will) get better.
You can get flats for the tone, but you will have to master the technique eventually regardless.
Note, if you are changing stings to something very different you will need to redo your setup. Plenty of threads on it here and a great preview video from Josh he’s working on here…