@Thomas_Gunther. Hey, Thomas! I found the mixer sliders annoying so I posted about that here and got some help. Trying to drag those little sliders is ridiculous.
I wish Dorico had the 1/2x and 2x tempo buttons like Cakewalk, but I sometimes just type in a temporary tempo and then delete it. For example if the piece is at 120 BPM, I will click a measure to select it, type Shift-T and then type q=60 in the pop-up box. After recording, I just click that new tempo and hit delete, or do another Shift-T to enter a new tempo. I am not 100% sure that solves your problem, but it’s a good trick to know.
I write orchestral music, and sometimes I enter a slow temporary tempo so I can hear what all the parts are doing.
All the best, --Konrad