I will only speak about this work alone as constructively as possible.

First of all, I want to point every positivity towards the voice actress, who I can hear that actually tried to make the product as best as possible. The voice actress totally committed to this work by what I can hear out of this work.

However, this comes the list of problems.
1) The recorder has no sensitivity nor binaural in-depth recording which is commonly from the microphones that are mostly recorded for voicing characters in most animation studios. The microphone which is used might not be the best for binaural recording. Consequently, the voice actress may be limited to perform any actions that absolutely requires binaural recording, such as ear licking.
2) With the part that exactly requires binaural recording have only less parts of the product, if the ear licking parts and perhaps the sleeping part are taken out, recording with normal microphones will work just fine. As a result, it means that there is no necessity to record binaurally.

There are actually more problems than what I wrote. However, those further problems may pose to each person differently.

I personally love Momoyama Ion-san, and I have been following and looking for her ear licking works. If you love Momoyama-san's performance, please check this work out. If you are looking for simulation, I can recommend this work. However, if you are looking for binaural authenticity, I do not recommend this work.

My appreciate to the voice actress and the team.