Hi peppyaf.
Welcome to the Mattress Forum! 
We have moved your post to its own topic and renamed it “sleeping hot …” to better describe your issue,
Sorry to hear that you are sleeping hot in your 1.5 years old Zinus mattress, but you are certainly on the right track with looking to place a component to help you get some distance between you and the less breathable memory foam underneath. This would be is a good temporary band-aid, until you move on to a more appropriate product. The temperature sleeping microclimate is a complex issue as it depends on so many interrelated variables… but you are correct that generally adding a wool topper will have a more significant effect on airflow, moisture transport, and temperature regulation than the other less breathable materials, layers, and components in your mattress.
Regarding the Amazon product link, you provided,… the 1" wool reversible pad manufactured is in China for Down Feather Healthy Bedding and looks interesting, but as with many new Amazon products, there is just not enough history, or details of who makes it … to have enough confidence. On Amazon, the product is displayed with an “Oeko-Tex” logo but again there is no other more specific info that a more transparent company would make it readily available such as i.e., date tested, certification number, manufacturer, etc. This is not implying that this particular product doesn’t have the certification but I’d make sure to check out that it has very clear certificates stating product and manufacturer, etc etc. This one of the reasons why TMU is so selective with our membership and why we point out to products from companies that we have a high level of confidence and knowledge. I’d recommend that you reach out to some of our Canadian trusted members especially MFC , one of our expert members with many years of experience in memory foam products and ways to mitigate temperature regulation issues.
While it’s not possible to quantify the sleeping temperature of a mattress for any particular person with any real accuracy because there are so many variables involved including the type of mattress protector and the sheets and bedding that you use (which in many cases can have just as significant an effect on sleeping temperature as the type of foam in a mattress). You have already made many adjustments in your sleep system to mitigate the issue, which quite frankly may have more effect on heat than any bedding or mattress product you find online. There simply is not any real credible data. There is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range. You may also wish to read more about the Sleeping Microclimate and Temperature Control in post #6 here that talks about all the many factors that are involved in the sleeping temperature of a mattress.
I’d recommend that you reach out to some of our Canadian trusted members especially MFC , one of our expert members with many years of experience in memory foam products and ways to mitigate temperature regulation issues.
I would be interested to hear back from you to learn what you decided and I or any other Expert Member of the site would be glad assist you with any other questions that you may have.
Phoenix