Mac version
We have a lot of issues when flashing from Mac devices, so we offered two options for mac users, one built over OS version 10 other for version 11. Fortunately you didn't seem to have issues.
So... ktool-mac is for the latest version of Mac OS, and ktool-mac-10 is for older versions? Interesting. I'm running the very latest update but I used ktool-mac-10 and it worked perfectly.
This was my install process:
cd downloads
shasum -a 256 krux-version_number.zip
cd krux-version_number
Make sure the Amigo is plugged in using the bottom USB port, not the side. Use Transmit app to give ktool-mac-10 permission to execute. (I use Transmit because it's an app I already have open)
./ktool-mac-10 -B goE -b 1500000 maixpy_amigo_tft/kboot.kfpkg