You know where that bolt body is gonna go if that bolt handle does not hold right? No way I would even consider that, twist rate will not matter much when you have a bolt body sticking out of your face/neck.
A 10 twist is much more appropriate for the speeds a 30Badger can create anyway. I have a 14 twist 30Herrett and I wish everyday that it was a 10 twist and I can drive that much harder than a 30X38 will ever be capable of. IMHO that whole slow twist/rpm thing is way overblown and does not even begin to come into play until you are talking at least double the speeds a 30Badger type cartridge is physically capable of delivering. If I wanted to shoot light bullets in a 30Badger I would choose a 9 or 10 twist as it matches the potential speeds much better.