Well,
I only edit styles using the keyboard itself, never used a software.
Why don't you try to remove the beats 1/2 in the style creator?
Changing time signature, I don't know if you can do it only in a section. However, you can activate the HALF BAR fill-in, and the fill-ins (including breaks) will be only half (2/4).
Maybe, maybe, only using the HALF BAR fill-in will solve your problem at all.
Regards,
Pedro