On a GO920, using navcore 9.701 (French language) with a patched (not SE) ttsystem and truck map 915.5113 ; ASR is working to find a spoken address (with or without dialog) for any vehicule profile. In this configuration, there is no voice (command) control.
On the same device, with a 9.701 SE version navcore and truck map 915.5113, in x40 or x50 emulation only, the voice control (microphone shown on the navigation screen) is working. (EPT is not supported by these emulations on GO920/930)
In x40 emulation, the vehicule profile can be choosen under Planification settings if initial setting was Bus or Truck. If an other profile is choosen this option disappear, so I suggest using x50 emulation.
In x50 emulation, the vehicule profile can be choosen by clicking its icon in the setting menu 7/7