Can you initialize a FTP DOTA session via AT commands if there is no application running (i.e. at+wopen=0) on the device?
No that is not possible.
The only option would be to use AirVantage Management Service. This cloud service is embedded in the FW and it is possible to install the OAT application.
Agree.
Or to have the complete DOTA application externally - using the module just as a dumb bit pipe