Conventional wisdom breaks down with the really long bullets. Because they are so very long, the lead core and thin jacket make them susceptible to torque. You want to avoid over spinning them. The RPM limit is greatly influenced by the number of lands and grooves.
You can use "advanced search" to go back into the archives about 5 years when they first became available and see how the RUM people fared and what twists they were using. You will also find the velocities they obtained. As I remember it, the 9.5 twist people had some successes and some failures but nobody with a 1-10 succeeded.
This is an area where you really need to do your homework beforehand