People tend to have individual reactions to sweeteners. But here's my observation (just of me, but it's something.)
Sugar free jello= aspartame, right? I find aspartame to be bad news. And there's waaaay better alternatives. Consider dumping this one.
Dunno about the dressings or spreads, but it's usually easier to just make your own. Then you can choose exactly what goes into it. Commercial spreads and dressings are usually full of cornstarch, sugar, HFCS, etc. Yuck. They're easy to make with a blender, too.
Not sure about the protein shake. I think most of them use sucralose? Its not as bad as aspartame by a long shot. It's not great either.
I think the best options are:
-stevia. My fave. But some people don't like the aftertaste.
-xylitol. It's more delicate in flavor, and you can cook with it. Give it a try.
-small amounts of honey. This is technically a whole food. Some people prefer it.
Sucralose (splenda) won't kill you, I have some sometimes, but it's inferior to the options above.
But you kind of have to try these out and see how you react, and then choose the best one for you.
Nothing 'once in a blue moon' is going to cause much significant damage anyway.
Getting my Grok on in the Pacific Northwest.
"C is for cookie, that's good enough for me."
"Cookie is a sometimes food."
"Sometimes cookie monster eat APPLE instead of COOKIE. Sometimes eat CARROT."
-Cookie Monster, partially reformed sugarholic