Is it possible to have an empty field in Field Groups which functions as a text area, that is subject to Conditional Logic, and does not have a field name etc ?
Here is a screenshot of what I have achieved as a hack using a dummy ACF text field, and some Admin CSS which hides the input box – http://imagebin.ca/v/2LBNjdJFQVuI
The problem with this hack, is that the field takes up resources on the front end by having a field name and key etc.
e.g. I have a True/False toggle, so when that is True, another item shows underneath it, in which i can show an image or some HTML for example. This would only show when seeing the ACF meta box on the relevant admin page, and wouldn’t need to take up any resources.
creative workarounds may be your only way to do this right now. There is this https://wordpress.org/plugins/acf-enhanced-message-field/ but it does not really work like a message field, but it does have a hide label button.
I will mark this for the developer to look at when he can, adding a hide label to the message field might be something he’d add.