I’m sure you already have good suggestions, but in case it’s of interest, I’ve used another approach for this situation. In Server Connect, I use a repeat after the query to determine if a related file exists:
The JSON returned for the repeat is:
… which I can use in AppConnect for the conditions, eg:
dmx-hide="!sc_search.data.checkImg[$index].fileExists"
The Set Value line is not doing anything useful but I think something has to be there.