I sometimes use a FeatureJoiner to correct data fed into the Left port. I use a StringConcatenator and JSONFragementer to generate the corrections, which are fed into the Right port. The FeatureJoiner's Join Mode is set to "Inner"; Join On specifies an Attribute from each feed that match each other 1:1; Attribute Conflict Resolution is set to "Use Right".
What I find is that conflict resolution is NOT applied Feature-by-Feature; it's applied to the entire set of joined Features. So, if none of my correction Features correct a particular Attribute in the Left feed, all of the Left Attributes bearing that name are passed through intact. But if even one of my correction Features corrects a particular Left Attribute, the remaining correction Features will replace the value of their corresponding Left Attribute with "<missing>". To avoid this, I have to add that Left Attribute - corrected or not - to every Feature in the StringConcatenator; what a pain!
Is this all-or-none approach the intended design?
I'm running version 2019.2.3.2 (Build 19825).