what exactly have you done to the code, I looked at your repo and can't see any difference in V1/V2 compared the the code from the original developer?
fwiw anyone who's had trouble trying to get the V2 code running, line 8 of the .ino code if you change
#define USE_DB2ID_TABLE 1 to #define USE_DB2ID_TABLE 0
it will run fine on a Mac, I fiddled with this about maybe a year ago and this was required at the time to get it to show up as a scsi device. Also in regards to the name of the device on lines 55-57 you can redefine what it shows up as i.e you could change the vendor 'TNB' to 'Quantum' etc just by changing those letters in the code at those line numbers I mentioned, basically line 55 is vendor, line 56 is model, and I believe line 57 is the fw revision.
I think the main reason the ArdSCSino isn't as popular as other devices is likely due to it being a little bit more difficult to program/upload the code for someone who's not as experienced with such things. I've be curious to know what read write speeds you get using this? I had pretty average read and write performance myself those the seek times were good compared to my Qauntum Lightning 730S drive. both were run using a SE/30
also worth noting you will need to create the HDD images on a modern computer and then copy those image files to the microsd card using the naming convention req'd in the .ino code. so for scsi id 1 it would be HD10.hds
just figured id share that as there not a lot of information on the Internet regarding the setup process