Displaying all parameter columns of a layer horizontally needs a lot of space, especially in a Layout or Detail. You need to scroll, and the names in the column headers are often cut off (which is why new users often overlook the Layout/Detail layer settings).
How about adding a vertical popup-list like this:
Could be invoked by clicking the selected layer(s) with ALT-LMB, ALT-RMB or similar. Changing multiple layers at once should of course be possible.
Given there’s no interest, would it be ‘straightforward’ to write this as a plugin in Python/ETO forms?