Required arguments on device flows

I have added actions to driver.flow.compose.json and I would like some arguments to be optional. Like described for non-device specific action flows, I have added “required”:false to the JSON definition:

“actions”: [
{
“id”: “SetMode”,
“title”: { “en”: “Set mode”,
“nl”: “Zet mode” },
“titleFormatted”: { “en”: “Set mode to [[acMode]], merit A to [[meritA]] and merit B to [[meritB]]”,
“nl”: “Zet mode naar [[acMode]], merit A naar [[meritA]] en merit B naar [[meritB]]” },
“$filter”: “capabilities=target_ac_mode1|target_ac_mode2|target_ac_mode3”,
“args”: [
{
“name”: “acMode”,
“type”: “autocomplete”,
“title”:{“en”:“Mode”, “nl”: “Mode”}
},
{
“type”: “autocomplete”,
“name”: “meritA”,
“required”:false,
“title”:{“en”:“Merit A”, “nl”: “Merit A”}
},
{
“type”: “autocomplete”,
“name”: “meritB”,
“required”:false,
“title”:{“en”:“Merit B”, “nl”: “Merit B”}
}
]
},

Everything works, except the “required” option. When defining the flow, both meritA en meritB arguments need to have a value.
Is this bug/not existing feature in Homey or am I doing something wrong?

Note: it does work on the web interface, so it looks like a bug in the app. Does anybody know how to register a bug for Homey?