[2020] MacOS: Is the memory leak a known issue?

I'm not across all reported bugs in this or any game, you could try searching the Bug Reports forum.

If this only happens with large mods, that doesn't really sound like a game memory leak I have to say, but instability caused by those mods. Have the mod authors commented on this?  

I see, we don't monitor the Steam forums I'm afraid.

Can you see if this has been reporting in the Bug Reports forum here?  

It is QA that monitor the Bug Reports forum, not the developers themselves. QA do read every post there, even if not responded to.

But are those crashes specifically the possible memory leak you mention, with the same mods you see these problems in?  

I do not know what the status of this issue is with QA or the developers, I'm sorry. I'm just an external technical support contractor on the other side of the world!

If you have a saved game that reliably shows this, please make a new thread in Bug Reports and attach it there - can't hurt!