Does the divorce-oath formulation: "By divorce, I shall never, ever, definitively, finally, not even once again, see anything forbidden" imply repetition, such that divorce occurs repeatedly when the oath is broken repeatedly, especially if the intention is to abstain from the forbidden forever and definitively?

The phrase does not imply repeated divorce unless you intend it or use a phrase that indicates repetition, such as "كلما" (whenever) or "مهما" (whatever). However, if you use a particle not intended for repetition, such as "إن" (if), "إذا" (if/when), "متى" (when), or "متى ما" (whenever), then the oath is dissolved by the first instance, and a single expiation is due, unless you intended it to mean "كلما" (whenever).