Hi experts. I'm thinking of adding feedback to a cnc retrofit and aware there are minuscule magnetic scales for that purpose. I do not have any experience with mag scales, just find them attractive (for now). I am unsure if they even work in an hostile machine-tool environment and so I thought I'd ask for "Pros & Cons" vs glass scales.

Q1: How 'magnetic' those are? Is this something that fills with steel chips every 5min or... how does it work for you?
Q2: What sort of signal those mag scale output? Same as the common glass scale's "A & B"?
Q3: Do they actually work?! Accuracy/integrity wise I mean...