[swamp2]

I also can answer the second question about an additional gear. Using the gearing from the 135i DCT and it's FD does not appear to add as much to the performance as just the shift time reduction. Of course this assumes that these gear ratios were fully optimized. Since the 135i and 1M have the same redline, and probably will have similar shaped torque curves, it is fairly safe to assume that a gear set optimized for one would also be very close to optimal for the other. Basic reasoning and experience also informs us that higher redline vehicles will typically benefit more from the extra gear compared to lower redline ones (i.e. M3 "needs" 7 gears more than the 1M).

#1 is 6MT
#2 is with 7 DCT and FD from 135i
#3 is with hypothetical 6 speed DCT

Keeping the turbos spooled is indeed an important effect. I'm not entirely sure if CarTest fully captures this effect fully. My guess is that is probably does. The "switch" in the software GUI for NA vs. turbo unfortunately appears to do nothing whatsoever. That being said CarTest does use a fully transient simulation and does obviously drop the rpm at shifts and then uses the new engine operating point for calculations just after the shift. Since the input dyno curves are always gathered under WOT and under load (i.e. no matter what boost is doing you'll never get more torque than the dyno curve) the torque available after a shift should be calculated assuming a best case scenario. With that understanding it might be the case that the negative effects of long MT shifts would not be captured in the simulation. However, for the short DCT shifts I think the sim should be matching the engine both before and after shifts pretty accurately.

Also you can clearly watch the virtual tach in the sim dropping to a higher post shift rpm in the 7 speed DCT compared to the 6MT, so that effect is again absolutely included.

Whether the sim captures the effect we know that in the real world, in the twisties and while driving at 8-9 10ths, this benefit of the DCT would be easily felt, noticed and could be measured.

Maybe someone else can comment about the ability of a single gear dyno curve to capture the transient nature of a turbo engines output (power or torque) just before vs. just after a shift.

On a very loosely related side note these sims provide my estimate for the top speed of a delimited 1M, it will be between 165-170. DCT or not the car is definitely drag limited in top gear.