Measuring reverberation is of no use in such a small room.
Reverb is a soundfield that's stochastic, so you have no direction, and it is calculated after the initial sound is down 5 dB. In a small room this is meaningless.
You could measure if there are resonances in the room sustaining certain frequencies in the vocal range.
If you view life with the knowledge that there are no problems, only opportunities, you are a marketing manager.......this is my personal philosophy