I did this on a previous project. I think that option to cancel de transparency when merged is more useful (because don’t breaks the layout flow). Think about it.
Having a hard time seeing why though, I feel like they would kind of negate the “merged” feeling? If the header wasn’t transparent, what’s the difference between having it on top of the page header vs inside of it?
With “position: absolute;” I must inspect the headear, get the height and add height+padding to the page header and test in mobile too. With the header merged, I just put a padding or and it’s okay.
Seems strange though. If you’re using the Page Header option to merge the header, and the header isn’t transparent- what’s the point? To show the background of the page header above it maybe?