For users that switch between languages a lot with Google Voice Typing, there is a wide feeling that automatic language recognition doesn't work properly, as shown by these discussions:
- Android Central: SwiftKeys and Google Voice Recognition
- Stack Exchange: Disable Google Voice Typing Automatic Language Detection
For us, this makes Google Voice Typing unusable on Swiftkeys. We speak English, it types French or Spanish. We speak English, it types Spanish.
For this reason, many people are asking for a key on the keyboard to let us manually set the language. Because we change languages often, this needs to happen on the keyboard, not inside Google Voice Typing settings, which would not work anyway (every time we switch languages, we'd have to uninstall other languages).
This can be an Advanced Setting to "Add key to manually set input language". To be usable, this key should NOT give us a huge list of languages, but just our "favorite languages", which are the ones installed in Google Voice Typing.
Please note that the Google Voice Typing API allows the developer to do that:
- In Reverso, depending on the direction of the translation (e.g. English to Spanish), Google Voice Typing opens with the correct language pre-selected.
- There are some keyboards that use Google Voice Typing and let you set the language manually (one of several SpeechKeys).

I, for one, would be willing to pay for a keyboard that provided some advanced features to give us greater control.