Last week I found a trick… at least on PC… the game might not be leaking but it hogs virtual memory. Default settings for VM might not be large enough and causing issues that appear like a memory leak.
Check out this link: https://us.forums.blizzard.com/en/d4/t/diablo-iv-has-run-out-of-memory/130683/103
It has recommendation on properly setting your VM so the game runs smoothly. I’ve been running most of last night and all day in HC with no problems.