Especially problematic for the portal/teleport flyouts for mages, I don't have the button icons memorized.

Is this still happening? I don't have a mage so I can't test. Hunter's at the very least have the tooltips for their CallPet ability. It should, in theory, work the same for mages

Tooltips are showing up but a previous issue has re-appeared, I'll submit that one separately.

On my mage solved this problem by editing the generated macro, and changed the c e.g. the "clickable" to m e.g. mouseover. Strange, but for the mouseover portals/teleports the tooltips works.

So, you can drag the teleport and portal spells from the spell-book, to the bar, and then right-click on the Neuron minimap icon (brings the edit mode), and right click on the particular dragged button, and change the c to m.

e.g. my mage now using this:

...
/flyout blizz:12:l:b:t:1:m

note the m.