Well.. there are some tiny pcie 2x slot lanes from PCH that are often put in idiotic place where GPU covers them etc ... sometimes it is weird, I use a riser cable and route those spare lanes elsewhere... well just to point out, that the lanes are there, but... damn... the slots are routed often in rather weird way.
I came from X99 where you had them enough... but it is an artificial segregation, things like that should die... the fun part comes, that the most rational pcie layout comes with most expensive boards and they kinda intentionally make some stupid arrangement for more budget friendly options just because for the more expensive ones have some advantage. I didn't do X299 because of mesh topology, those CPU's suck at gaming and cost and arm and leg and offer you nothing more and HEDT really died recently as a thing, I do not treat Threadrippers as HEDT as those are different animals, more like home chibi server rendering farm. ie Like in old days I had Tyan Socket F duallies. The distinctive feature should be good at overclocking.
