What's up Brandon? I have been flashing nb0s again, and while I was on Sharp 2.3.5, I had to use tjstyles recovery, because of the kernel. While I was messing around I figured I would see if usb would mount, and it did. I personally have never seen the usb mount in recovery, so this is my first proof that it can work. I know it is a different kernel and the recovery is built from the kernel but I just wanted to let you know. I believe it was 5.0.2.7 but I have refreshed my phone to stock since, so it's not there anymore. I know that most of the X6 recoveries worked on our phone, just different button setups, so I am gonna take a look and see if any of them will mount the SD.
I also pulled a kernel config from the stock Sharp 2.3.5 kernel which I believe is 2.6.35.7. Plus, I found a 2.6.38.6 kernel that has our camera driver, it is the highest version that I have seen that still has the mt9m111 driver. And it is different, I still have to see if it will work in our kernel to see if it works. I know you are not working on kernels at this time but just thought I would put it out there.
Sharp235_defconfig.zip