Hi Emanuel, nice to hear from you - TE is not a good idea with the 1305 - works ok with the 1085, but can tell you from own experience the 82 or 90 TE will not handle the strain of the jumps with the 1305 - that's why we recommend to only use the stiffer normal Carbon Mast.
90 vs 82 - I keep switching back and forth between the 2, depending on racing/downwinding (90), freestyle (82) or waves (82) in shallow water - in the end I will probably end up using the 90 pretty often, as you just get used to the extra time it gives before breaching, this really makes a big difference - stiffness is a touch less obviously, but more than good enough for 1305+. Lightweights using smaller wings can easily use the 82, as a good allrounder, especially for reefs or shallow lakes..