The carbon shaft for a playing cue should be a different to that of the carbon shaft for a break cue. Funny thing is the jump shaft can be the same as a playing cue shaft, but a masse shaft can be the same as a break shaft. The tips for all 4 can or should also be different. Depending on the person.
Nothing wrong with getting a carbon shaft made for your cue for what you want it to do. Just that a one off is alot of work unless they are already making good dedicated break shafts.