If servo transparency and jack stall are being used interchangeably and incorrectly, could somebody explain the difference?
As to servo transparency in the 350/355-
In more foolish days, I'd fly these like ordinary state-side helos.
Flown vigorously- Say, at better than cruise speed- load a little "G," like a zoom and control RPM with collective, add a turn- and the normally impressively agile aircraft's cyclic will stop moving in one direction( or you'll get a "limit" light in a 355). A little less turn (left, last time), or a little less collective and you get some back. Load it again, even with less pitch- and there's the wall, once more. It ruins your plans for hotting up the dog. If there's something that you were turning or zooming to avoid, well- too bad- you're not going to push the stick in that direction, right now. I hope it's a forgiving obstruction, or you left an "out."
I've never encountered this in any other mode besides playing around. And never in any other helo.