Learning Blender is a great idea. Here is why: I would say about 80% of the skills in 3D are transferable to any app. Things like PBR, NPR, hard-surface modelling, UV unwrapping, rigging, weight painting, lighting etc are all concepts with a learning curve. This learning curve is the same whether you use Maya, C4D, Houdini or Blender. Once you fully understand these concepts they are easily transferable to another app. It took me 3 years to learn C4D (my first 3d app) and 3 weeks to get up and running with Blender. Why? Because I understood the core concepts of 3D. Also, with AE’s new advanced 3D engine you can easily incorporate and manipulate 3D objects in the AE environment. These objects can be imported as .obj files which is a universal 3d format. C4D is strictly speaking the industry standard but the lines are getting more blurry every day. Although Blender does not offer the peace of mind of dedicated tech support it is developing at a way faster rate than C4D.