I agree with you statement. Sony person must fix mulfunction.
I experience same phenomena in A7R2. I'm really annoyed by this "bug". My current environment is firmware v3.0, Remote Control App v4.10. This phenomena has kept from firmware v2.0 and Remote contorol App V4.0, as far as I tried.
I make one-line command in Linux to prove mulfunction. Results are below.
$ one_liners/setShutterSpeed.py 0.8 {"method": "setShutterSpeed",
"params": ["0.8"], "id": 1, "version": "1.0"} {"result":[0],"id":1}
$ one_liners/setShutterSpeed.py 0.6 {"method": "setShutterSpeed",
"params": ["0.6"], "id": 1, "version": "1.0"} API camera failed.
{"method": "setShutterSpeed", "params": ["0.6"], "id": 1, "version":
"1.0"}
$ one_liners/setShutterSpeed.py 0.5 {"method": "setShutterSpeed",
"params": ["0.5"], "id": 1, "version": "1.0"} {"result":[0],"id":1}