I like that you're being explicit about how you're passing arguments.
Private Function GetModelProps(ByRef swCustPropMgr As SldWorks.CustomPropertyManager, Optional ByVal dicInput As Scripting.Dictionary) As Scripting.Dictionary
But I can't find an instance where swCustPropMgr is being assigned to. As such, you can pass it ByVal too and eliminate an ...
Also the naming guidlines doesn't explictly mention variable local to a method, you should name them using camelCase casing.
Naming methods, properties and variables in a meaningful way will help you or Mr.Maintainer to faster grasp what a variable/method/class is about.
Shortening of names like foreach (string s in drwPaths) should be avoided. ...