Integration with Search api view

Hmm, I didn't try. Could you try and report the results?

Tested and the module did not worked out with SearchAPI based views; I run my tests on a commerce-product index, where I am trying to apply this module to filter the "nodes referencing this product".

SearchAPI is actually replacing the the filter handlers with its own classes, thus (AFAIK) avoiding this module to be integrated. I will try to further investigate this integration, even I solved this with a custom module that injects some code in the "options list" of the commerce_product_reference property.

Maybe some patches will follow?

@maximpodorov: I ended up not using this module, not patch to provide sorry!

A preliminary patch to let the module work with SearchAPI indexes and queries.
The code is taken from SearchAPI handling of queries and constraints building.