Render Elements Only is Taking Ages

Corona Corona for 3ds Max Help Required
1

So I needed to render a Masking Element for a single Object ID and using Render Elements Only it took like 50min to do at 5k resolution.

What am I doing wrong? Do I have to change the number of passes, currently using 80?(wouldn’t that be a problem if I was doing an AO elements or something though?)

2

-What is your hardware? Is it possible that simply rendering 80 passes in such resolution took so long?
-Do you need these 80 passes? Is the quality worse if you render less passes?
-You are using the “render only elements” button, right?