Here's something I've been working on along similar lines: https://github.com/rustyrussell/bip39dice
Haven't published it yet, since it needs a helper video and some serious analysis (i.e. how biased are normal dice, and how biased is hand rolling) and of course concrete recommendations for the final word fixup.
But being able to *verify* that your phrase is random is far better than other approaches, if you're going to roll...
