Hello @nyper
Thank you for reaching out and I am happy to assist you with this.
As you already know, W3 Total Cache preloads the Pages when Cache Preload is enabled in the Performance>Page Cache, and it’s doing its work by crawling through the pages using the sitemap you provide in the settings Sitemap URL: field.
This also works with custom sitemaps, so the only way to achieve preloading only specific URLs is to create a custom sitemap that only contains URLs you want to preload.
You can check more about this in this link or check with the support of the SEO plugin you are using if this is possible.
I hope this helps!
Thanks!