I routinely set garden variety FL dies to produce two or three thousandths shoulder setback. While this doesn't size the case as much as the die may be capable of doing, it does size the entirety of the case and so is full length sizing. It's just not full length sizing more than necessary.
I would contend that that it is proper full length sizing.
I generally try for no more than 1 thou set back on the shoulder, but then I have dedicated brass for every gun.
