Caching and Performance Issues due to set-cookie header of Curcy.

This is the message which the WordPress.com technical team wrote us concerning set-cookie which is blocking caching of our site:

“The issue we have found with Curcy is that these plugins add a set-cookie header to each request, including the homepage. This can cause performance issues as it invalidates any attempt to cache the pages. Caching allows us to store a copy of a page and serve it quickly if nothing has changed. Not being able to cache the page means that it has to be generated from scratch each time it is requested. This ties up PHP workers that could be used for other functions and slows down the page load.

Regarding Curcy (also know as woocommerce-multi-currency), we found documentation that mentions using the PHP SESSION variable instead of the COOKIE variable at https://docs.villatheme.com/?item=woocommerce-multi-currency. This states Use SESSION: The plugin will use the session instead of cookies to save the selected currency. We did some testing with this option turned on, and the set-cookie headers for the wmc_* cookies were removed, however, they were simply replaced with a set-cookie header for PHPSESSID which again is likely to block the caching. In this situation, we would suggest reahing out to the developers of Curcy to see if they are able to achieve what they are trying to do without using the set-cookie header at all. It’s worth noting that with this plugin turned off, the initial pageload speed increases significantly.”

Can you please let us know how we can resolve this issue?