BIK: Full Body IK Solver

Hi, this looks like a really great plugin made with love.

  1. What are the pros and cons in comparison to Ikinema UE4 plugin ?
  2. What are the limits for indie license ?
  3. If I get it right, this is closed source plugin. UE4 is changing very fast, so what happens if I buy this plugin and will stop developing it and adding support for newer versions ?