The transmission holds the gear until the engine hits redline, it is like that by design. I don't like it very much either which is one of the reasons why I only use dynamic mode for the occasional take-off from a standstill. The others reasons are significantly poorer fuel economy and lurchy feel. Comfort mode works well for 99% of my usage.
Same here, I use comfort mode 99.5% of the time. It's the holding of the gears that I don't care for in dynamic but I do like the quicker launch so I use it for that on oaccassion. Flooring it in comfort does 'get up' but, at least by my butt test, dynamic just launches the vehicle so much faster.
This engine should have adequate torque at 3000RPM to start off in dynamic mode. It is not racing mode so should not hold gear till red line IMHO. It is a concern for people hitting this and worried if anything wrong with the gear box.
Acceleration is how soon it revs up to red line. People are not trying to accelerate fast, so they maybe just slowly press down the gas pedal and the car does not get to expected speed because it stays at 20-30mph without gear shifting.