Takes too long to render a product display with 6000+ variations
Didn't find a proper solution to increase the performance or, at least a clean solution. So I decided to create a module that basically holds an alternative view formatter to the "Add to cart" that comes with Drupal Commerce.

You can find the module here: https://www.drupal.org/sandbox/marcofernandes/2705035

Basically it's a "clone" of "Add to cart" view formatter but it avoids iterations over all variations and field options. It's not perfect but it fits my needs (variations for all possible combinations). I'll keep it as a sandbox until it reaches a more mature state (it lacks some validations and, probably it misses some code styling).