It is practically the same thing only without a GUI with dummy.
You work directly with bones and rotate them respectively.
There is bug with Mirror check box where you have to uncheck and check back for every other bone you work with, which I meant to report for a while. Now it's in:
https://www.reallusion.com/FeedBackTracker/Issue/Pose-Offset-issue-with-Mirror-check-boxHere is how you do it (I have also shown the bug):
And do not forget about this new feature called Proportion - a great way to quickly rectify body disproportion without any sliders.
Like in this case I would've first moved clavicle bone to widen shoulders a bit before using Pose Offset.