While creating our GDPR compliance database I've had the unusual (in my case) opportunity to create a FileMaker 16 (188.8.131.520) database from scratch on my Mac, I normally work on Windows via app streaming customising our standard SaleFaith CRM systems. It has been nice not having to worry about legacy themes and formatting.
It is interesting to see just how critical the position of an object in an object still is, possibly slightly worse than on Windows, and the design compromise/adjustments that are necessary on both platforms.
I got the normal infuriating portal showing through all tabs and having to nudge it one way or the other, or put more distance between the vertical or horizontal edges than I wanted. This has been going on since version 12 and really should have been fixed by now.
However, adding text to popovers to act as on screen help/tooltips has been interesting. We've no padding around the text but I've found it impossible to select the first line entered when trying to edit existing text, in fact the only way I've found of doing this reliably is to double click the third line of text, which does enter the text cursor and then use the arrow keys, but anything above this just selects the overall text box and/or brings up the Popover Button Setup window. No problem selecting the end of the text, only the top.
Then if the text is too close to the popover content vertical or horizontal edges, during opening, an annoying vertical or horizontal scroll bar appears that doesn't look good. Increasing the size of the popover a little or decreasing the height or width of the text will remove this and speed up the opening of the popover. I believe these scroll bars also display on Windows, but I haven't tried editing them in layout mode to see if this is Mac specific. I've attached a screen shot having reduced the size of the popover to demonstrate.
These are small issues, but do have a significant productivity hit when setting up the amount popover help objects something like the GDPR system needs (I will check whether this has been reported on 'Report a Problem')