Plugin Slows down website

Hey there, ty for your plugin, but i got little problem with it.
It works great and all, but slows down website significally. I installed Plugin Organizer and tried disabling woo-poly-integration – that gave me a nice speed boost while serfing pages of my website, as well as increase in PageSpeed rankings from 65 to 88 score.

I then tried to enable your plugin only on needed pages, like Checkout/Cart/Basket etc(on both language versions – default and English). It also worked out well, but with only one small flaw that i can’t fix.

After submitting order on checkout page in English language i somewhy get Default Language Thank you page ?? Instead of English version of it. I know that there is no thank you page and its just a checkout page with thankyou.php content. After submitting order language somewhy switches back to Default. Same behaviour was when i go from Cart -> Checkout and woo-poly-integration was not enabled for this pages. Now its enabled, enabled for children pages and for logged/not-logged, but still can’t get thankyou page in English.

Enabling woo-poly globally solves it but slows down webpage. How can i solve it ?
Thank you