Is placeholder and instructions no longer working in maniphest.custom-field-definitions?.cu

I was reading the docs about creating custom fields, but cant seem to get the instructions or placeholder value to show… The docs show that both fields can use remarkup, so that is what I am using. The required does not show also unlike the Title field in the default form.

What am I doing wrong?

My JSON value for the custom field is:

{
  "mydata": {
    "name": "data",
    "caption": "Enter my data",
    "type":"remarkup",
    "placeholder": "Use {icon cloud-upload} to upload files.",
    "instructions": "NOTE: Give me some data",
    "required":true
  }
}

If I then go to create a tast, I do see my new data field present, but without any of the information from placeholder or instructions.

Feature request

Would be awesome to have a field type dedicated to file uploads.