As you possibly know Wireguard hasn’t something like “DisallowedIPs” parameter to exclude some networks from allowed ones. Of course technically AllowedIPs is enough, but I am tired to calculate it by hand, so created this simple calculator:
Source From: https://krasovs.ky/
Another: https://www.procustodibus.com/blog/2021/03/wireguard-allowedips-calculator/