Tom... I really think that a CNC controlled job is the best... over the years, I've seen 1911 slides (.38super and 9x25)really whittled away and not have a problem... the only Glock slide I've seen fail, was a very high round count USPSA shooter, and the slide cracked vertically at the front of the ejection port....
the precise milling by BattleWerx on my RMR, IMHO locks the sight in place very well to combat slide acceleration stresses about a week turn around and half of that was USPS small package