Well, actually, it was not resolved regarding CSS specificity, as I said in the other thread.
None of the more specific CSS suggestions, or others I tried worked with Add Admin CSS to removed the buttons as suggested.
Adding it via a function did work, though, so it seems something about where/when in the page flow Add Admin CSS was adding the CSS did not work to remove the buttons in question.
Add Admin CSS seems like a great concept for a plugin — albeit overkill for one item like this, perhaps — but it did not work in this case, so I ended up overriding the CSS via a function as was alternatively suggested.
-mpm
Some time Add Admin CSS plugin faces issue with the CSS code containing spaces in that case you can just try removing unwanted spaces from CSS code like following.
.csb-pro-layer{display:none !important;}
