ProEXR now supports Cryptomatte

https://www.fnordware.com/ProEXR/

ProEXR is a free plugin for After Effects and Photoshop that makes dealing with multi-channel .exr files a little easier in a layer based compositing program. The team have recently built in Cryptomatte support, which is really handy, and so far as I am aware, it is the only way to get Cryptomatte support in After Effects at the time of writing.