Seen a few posts asking about compositing post-render so I’ll throw up my YouTube video here for anyone interested to learn how to do the basic compositing in Davinci Resolve Fusion when exporting in OpenEXR Multilayer from Blender.
It may not be a great video but it could point you in the right direction 
Not touching on Cryptomattes in this tutorial but will probably do one once my next Art work is finished & i’m compositing once again
