Well, I will leave it to you for testing and reporting if anything is not working.
First, install the original plugin and when asked for the license in the pop-up window, click to use the free version. That way we are "priming" the database with the default values.
Then, install the modified plugin below on top of the already installed plugin. That will take care of the premium options by enabling them. Just test all the functions to see if everything works fine before committing and putting time and effort into using the plugin in your website so not much is lost if it does not work..
I also enabled the "white label" option so the "account" tab will not show (not needed anyway).
Again, it is a shame that it won't work with Woocommerce's HPOS technology, but I understand that you are already comfortable with the plugin mechanisms.
Plugins protected with Fremius are good for the developer but a headache for the plugin cracker xD
DL:
Code:
https://www.mediafire.com/file/00y1lg1c5zxh4cg/premmerce-woocommerce-product-filter-premium.zip/file
VT (0/58):
Code:
https://www.virustotal.com/gui/file/458a61aa6e947e0eefbe25889fdd559e63d55d6591c448ded539172aa2a7b554