I found the same thing in my tests here. I ended up using HFI gain set to 0.100 and it solved that issue completely (trampa hardware, and stormcore 60d+). The stormcore made an audible whine when using sHFI, and the trampa esc was nearly silent other than a loud click when sHFI engaged.
I’m considering using the BioX for my next 4wd build to avoid using sensors and sensor extensions.
What did you find the noise like on the BioX when using sHFI?
I can record a video with my board this weekend. It’s silent, maybe a little sound when take off.
Ok tested again. Reacher 6495 motor and BioX. It was silent just like hall sensors, could not hear any real difference compared to hall sensors.
Wow, sHFI is silent, except for that little click when you first engage the throttle.
Really impressive to see - thanks for the video 
I will give it to you that is the quietest one I’ve heard yet
Still stuttering a bit though, that’s a shame
That’s smart reverse, other way it doesn’t
There’s literally no stuttering in that video. It’s smooth AF. The only thing I hear besides the “click” at throttle engagement is the smart reverse bearings/gear noise.
Literally at 8 seconds lmao - it is smart reverse though
Good to know theres something other than trampa that can basically achieve silent hfi, although I think it would still be hard to trust a spintend based esc after how many I’ve seen burned up
One local rider runs his at like 160 motor amps per side on 16s, it’s ridiculous, he must have a good one lol
I don’t know what you consider a stutter, but that is normal smart reverse to me. There is zero cogging there. It’s just as smooth as smart reverse with hall sensors. Just the normal smart reverse noise.
The right motor 100% stuttered when going into reverse. And no that’s not just smart reverse
If others are seeing it, then I’m missing it.
Sometimes it feels like folks want shfi to work as well as sensors do so badly that they start hallucinating
(Mostly joking, don’t take me too seriously)
if you would just be so kind to let me live in delusion, I could do my mountainboard build without running sensor extensions.
I will make some for you. DM me the specs and your address.
A friend runs his 75v v2’s at 150A/side without issues as well.
I run my v1 at 120 motor amps per side, 65a battery
Never even had an OC fault 
Only 12s though
Unlimited firmware?
Yessir
Probably still going to swap at some point for peace of mind, but man my ubox doesn’t seem to want to blow up
I remember not long ago everyone was pretty scared riding 12s boards bc of lack of vesc that can handle the voltage.
Nowadays 18s seems standard in here lmao
Tell me about it bro, I was trying to build a future proof board and now all I wanna do is swap the battery for a HV one 