Are you going to add the Office 2013 styles to the TAdvFormStyler/TStyleForm? Including switching to/from Metro?
TAdvFormStyler.Style can be set to tsOffice2013White, tsOffice2013LightGray, tsOffice2013Gray in the latest version. Did you try this? If so, not sure what exactly you want beyond this?
I have many dialogs in one particular app. I tried descending them from TStyleForm and they are close.
However, they do not look the same as a form descended from TAdvToolbarForm with an AdvPager. The corners are not square and the form header is a little different.
I ended up descending the dialogs from TAdvToolbar form with an AdvPager with no pages. I had to add a couple of things in WMPaint, but now they look like 2013 dialogs.
I am satisfied with this approach.