dearVRmonitor works great for monitoring through headphones! Also, several DAW's include free binauralizers in them, Cubase and LogicPro with their atmos support both provide. Might be others as well, those are the only two I'm aware of. But I think dearVRmonitor sounds a little better then the one built into LogicPro.
The one advantage I can think of for having built in binauralization inside MP3D would be that I think it would substantially reduce the CPU requirement by encoding to binaural before sending back to the DAW...thus drastically reducing the DAW's mixing requirements in terms of audio channels. My Computer can barely handle 5.1.2 with 100 tracks...7.1.4 was totally out of the question and I believe this was mainly due to all the audio channels coming back into 100 tracks in LogicPro. If MP3D had option to encode to binaural, then I have a feeling I could use any of the MP3D output formats...and even work with 7.14 and use less CPU. Just a theory.
This is not as simple as just adding a binaural encoder though because MP3D is designed to pickup the channel count from the DAW's current mixbus channel count. So things would have to be modified considerably in order to handle the DAW using a stereo bus, but expecting MP3D to process 7.1.4 and encode it to binaural stereo.
Macker another thing to consider is that binaural is most likely not the format that you want to bounce or distribute. its just mainly useful for monitoring purposes only. Well if you are mainly just interested in writing music on you own and not sharing it with anyone anyway, then its a moot point. But if you plan to distribute it, most likely you would want to distribute Dolby Atmos, which means you would want the full 7.1.4 (or 5.1.2 in my case) but being mixed in you DAW so that you can ultimately generate an ADM file, which ultimate produces a Dolby Atmos MP4, which ultimately is how most people will be able to listen to this kind of content if and when you will be distributing it. So really...working with the full surround bus in your DAW is the right thing do to....if your computer can handle it... You can then monitor it from there as binaural if you want or quickly turn off that binaural encoder in order to monitor through real surround speaker config...or to generate ADM from that mixbus using tools in LogicPro.
It all depends on personal expectations, habits, and most of all: the physical shapes of heads and ears. As the most obvious example let me point out that I actually happen to like DearVR's binauralisation a lot. 
... in the end it's a somewhat pointless discussion anyway, considering that commercial releases will have to rely on Dolby's or Apple's algorithms most of the time, like it or not.