With this info you should have a performance base point and then be able to raise graphical settings until performance slows down.
I am now running this game smooth as butter for a over week now, I have all settings to low, any setting that increases performance is either chosen depending on which one increases performance for enable/disable options. Now this all helped a tiny bit, still the game performance felt sluggish on my 2019 Macbook Pro 16 inch with i9 using boot camp in Windows 10.
It was after I changed the rendering resolution that this game woke up and my FPS nearly tripled. Also now you may be able to bump up some of the quality settings to make the game look a bit prettier one by one to find a good balance. Performance wise it’s as fast as D3 plays on same computer. In the D4 settings you can run lower graphical settings and make them look better by raising the option for ‘Sharpening’ that is set low by default. This is just like a photo or video editing option so use a bit I’d recommend around 30%, alternatively you can lower it and get a more glow look.
Another change was in the AMD Radeon™ PRO Series Graphics app I ENABLED ‘OpenGL Triple Buffering’, an alternative vsync mode. This was mainly for other apps on my system and not D4 but I just mentioned it anyway.
TLDR in D4 turn all options to low and choose to enable/disable any option that will increase performance, then set the ‘Performance’ settings like shown in the image below. This is a good starting point to find a good balance, then you can raise some quality settings one by one until you you find any that slow performance and reset them. Adjust sharpening setting to get more quality 30% is usually decent.
The settings are shown below in the screenshot image.