So your low end of the voice is at 140 Hz, which is actually quite normal post-VFS and considered a rather good result. Most of the girls from Yeson have that pitch as the lowest or even are a bit lower if they push it. So this sort of confirms my suspicion that your voice is in part sounding not that great because you are speaking at the lowest pitch possible with your voice box now. It would be like me trying to speak at my lowest pitch which is about 85-90 Hz - I would strain, I would break up, I would sound weak. I would thus suspect that your natural speaking pitch should be above that, at maybe 170 or 180 Hz actually. Now why you cannot use that pitch for speaking, I am not sure. Maybe it is what others described here as having your brain trained to use the new pitch. Its what some people who had been at Yesons are struggling post op as it gives them the impression that it did not work out. It is still a bit of a mystery why it happens.
The highest pitch in the recodring is just 300 Hz flat. This is rather low. I would say , you are using only the chest voice. I heard before that CTA can eliminate the break between chest and head voice and basically only allow one voice to survive, as it turns off one of the two muscles who would otherwise do the switch between the two registers. Maybe this is what causes this, but I would expect that you have a break at 300 Hz and just feel like you are stuck underneath. Can you squeak or giggle or scream or sing in a higher pitch than that? It can be MUCH higher if that is of help.
Are you originally Japanese? How well did you learn english? I do not know japanese gender voice differences at all, but maybe it would be good to do a voice therapy in english as well to get the melody and prosody there. But I think what you would need is a more general approach, not about speech but about voice. Trying to break free of the 300 Hz barrier there and to allow you to access more pitches, and also increase your speaking pitch into the mid of your new speaking range.
your comfortable note is at 240 Hz, this is WELL within the female range. If this is what comes when you totall relax the voice, my assessment would be that your voice surgery was not botched but is still holding, but something must still be wrong. The parameters then would speak for a successful voice feminization: 140 Hz as the lowest note, 240 Hz comfortable relaxed pitch - the negative is the limitation at 300 Hz which may be what pushes you to speak generally lower as otherwise you would feel that limitation while speaking.
The main goal would be in my opinion now not to increase pitch any further with another surgery, but rather see how you can regain a healthy voice and reach the upper pitch levels that seem to be blocked. In addition to that, it would probably be good to check generally for voice health, I guess Dr Kim would say you have a strong vocal tremour, so get that checked out by an ENT and see what the diagnosis is, I think some of it may be helped with voice rehab and I think it would probably be a good idea to do this before doing another surgery. In the worst case another surgery would increase your low end of the pitch range even higher to 200 Hz but not change the upper limit, then you would be locked in a 100 Hz pitch range and can never be anything but monotonous. I think to solve the riddle why the upper limitation is there is a priority. if it really is from the vfs and can be somehow reversed, then it has to be done, if it is something else, maybe voice rehab helps
To give som courage - I felt locked in a low range as well. I had that breat at maybe 350 Hz and thought I can not go beyond that without the voice breaking or cracking. I knew however i can giggle or sing a note or scream at a higher squeaky pitch, so I managed to build a bridge between these parts of my voice and use the full range when I use a female resonance.