I just did a cursory internet search and one thing I hadn't thought of was that with enough resurfacing eventually the disc springs are going to hit the crank bolt heads.
I tore up a clutch disc my senior year in high school. It mangled the brand new Hayes FW I had. My HS metal shop had a lathe big enough to swing a FW so I stuck it in there, indicated it in and started taking cuts.
That clutch always had a bad shake to it. I found it it wasn’t machined parallel to the crank so I trimmed it off until it cleaned that up.
And the springs on the disc hit the crank bolts. I was pretty pissed I didn’t catch that before I started machining on it, and my shop teacher gigged me pretty hard for that one.
