Just commit, no matter the response. Adding /s is akin to explaining a joke after you tell it. If someone doesn’t understand or pick up on the sarcasm, it’s not your responsibility to spell it out for them. You add /s because you don’t want to be held accountable.
Exactly. We all have nuances in our sarcasm, mine is very dry and sometimes I honestly don’t even notice I’m being sarcastic. I learned I can’t use it on people who have never seen it before, or rather if I do be expected for them to take my literally.