I disagree with Preponderance for philosophical and practical reasons, certainly as a uniform standard. It’s arbitrary, at odds with the rule of law, and with negative liberty. This is especially so when it’s not a jury who assesses things.
Clearly it’s possible to list examples of acts that just barely cross the threshold to “harassment”. It’s legal definition necessitates that, incorporating severity, and repetition. Whether it’s opportune to do so is another matter.