And, Apache OpenOffice does work on it, so I’m good.
FYI, this is a temp computer. I normally use an early 2011 (still old). But, at the moment it is on the way to the states to get the video card replaced. It is part of the non-voluntary replacement Apple does for free as long as I own the computer. I work in Papua, Indonesia where there are normally high temps, moisture and very fine dust in the air, even in my AC cooled-rooms. They may be on the hook for a while with me.
iMac since 2011.
No issues with upgrades.