Tom is right.
The 70 cm carbon makes no sense for anything but SUP or surf foilers, who want it light.
NOT for kitefoiling
Of course there will always be a very little niche of people liking it, but not in general...
A 70 cm carbon mast can be used in the early learning phase yes, but when learned, you got an expensive 70 cm carbon mast you can not use nomore, and difficult to sell...
Get a short alumast for starters, can be sold cheap, or kept as it cost almost nothing, or start directly on a 90 or 100 cm mast
Peter