I agree that the EyeX Interaction end product, when it claims to be compatible with voice commands, should provide an easy way for end users to combine.
The problem is that the EyeX Interaction module is still in alpha/beta stage, and still only supports keyboard and mouse input. In this stage, we do not want to recommend anyone to build software that relies on functionality in EyeX Interaction.
If you have built a little program, based on the EyeX SDK 1.X (which will be stable as long as the EyeX Engine version is 1.X) that helps voice control users to combine eye+voice data, I would recommend to publish it as a plugin to Dragon user groups or similar channels. Maybe you can even make some money on it, and Tobii gets to sell more eye trackers. Win-win, that’s what developer communities are for!