Sollumz cannot import binary formats directly. You must convert them to XML first using CodeWalker!
Since this plugin was designed around CodeWalker's XML file formats, OpenIV is not explicitly supported. You may experience issues going from Sollumz > CodeWalker > OpenIV. It's highly recommended that you just use CodeWalker.
The following is a list of unsupported ped YFTs. These YFTs contain unknown ragdoll physics data that is not handled by Sollumz. Currently, it is not possible to create completely custom player skeletons.