Tensorflow on MDBT42Q ?

From time to time I spent an hour or so for speech recognition.
There is an example https://github.com/tensorflow/tensorflow/tree/master/tensorflow/lite/micro/examples/micro_speech for tensor flow lite.
One of my open questions is microphone.

• simple microphone would expect fast A/D conversion.
  
• I2S microphone (like INMP441) needs an I2S interface.
  At the end, both solutions need lot of memory, which will not be available on all boards.
  Last not least, see problems with adding tensorflow on MDBT42Q board in other chat.
  Any nice idea, how it could go on ?