Hi again @JustinReynolds, thanks for your suggestion. I noticed you were very active in the forums about this topic within the last few years so you have a lot of knowledge about these expressions!
I am curious to see if you have experienced strange functionality between the calculated expression and editable expression. For example as I mentioned above, the moment I have a secondary condition in addition to $editcontext.editType, it wipes out my existing field instead of retaining it. I fixed this by adding a few lines to my calculated expression with an if statement of $editcontext.editType == "UPDATE" to retain originalFeature's field.
However, I still have really weird behavior in other cases such as:
1) If my editable expression is == "INSERT", so that I can allow edits after it is autocalculated, the calculated expression does not work at all so it is left blank (perhaps that is intentional by Esri)
2) On top of that, if I have a condition in my calculated expression to autocalculate the field if there is a specific string existing in that field, that only works if I have no editable expression at all. If there is no expression and it is an update, then the field gets overwritten correctly. If there is an editable expression as $editcontext.editType == "UPDATE", then the field value stays. No difference in the actual calculated expression, but depending on what's in the editable expression, the behavior is very different.
I am already talking to tech support about this but given your experience I figured I'd ask!