I think this would take a ridiculous amount of time to generate a private key, plus the fact that rolling dice this way is going to both increase the chances of making an error as well as you getting impatient and just using "random" number from your head part of the way through the process
Obviously you didn't try it, did you? With 6 dice you only need 17 iterations of the loop "roll, write down", easily done in under 3 minutes (at 10 seconds per iteration, which is more than enough). No faulty/compromised RNGs, just pure entropy from the universe, no source code needed. You only have to take care of reading the dice always in the same order, eg. start at yellow and go clockwise.