I attempted to use the built in expression mixer to create the 52 shape keys for ARKit as expressions. Here's how to make the most out of this - 1 - In Make human apply one of the 52 expressions to your character 2 - Import the character into blender - I use MPFB with the 'create character from makehuman' option to load the character from a running instance of makehuman. Ensure the first time you import them they don't have any expression - this will be the basis shape key. 3 - Switch the expression in makehuman to one of the 52 shape key expressions, and import your character with this expression. One thing to note, for making shape keys, I recommend saving a preset that just imports the body proxy, eyebrows, mouth, tongue, eyelashes, and of course eyes. Once they're in blender merge everything to the body. (Do ensure everything is merged to the body proxy, not doing this in the same order for each key will cause unexpected results). Ensure when you import the body proxy it doesn't have any subdivisions, modifiers etc. 4 - Once you have it imported, and merged, you can then use the join as shape key option, making sure to give it the correct corresponding name. 5 - repeat for each shape key. It's a lot of work but It only has to be done once per character - and then you're ready to animate. It's not perfect, but with some slight adjustments to the finished product you can get decent results. I noticed that the shape keys used to stretch the lips and smile are additive, so you may have to tune the animation curves/lessen the intensity of those. But that was the only modification I needed to make. It's a start. Just unzip and put the expressions in your expressions folder, and they should show up in Makehuman.