Query site collection for specific content type and display as a list

I’m working on a main page for a projects site collection in SharePoint 2013 on-premises. Each subsite is a project based on the same template. Using a CQWP with a custom display template, I’ve managed to pull all project data from the same list (based on a custom content type) on each subsite and display them as a dashboard, but I can’t figure out a way to display column headers. I know it’s possible using a CSWP and datatables.js, but my department wants instant updates when project data changes.

Based on these requirements, I’ve been looking into using jquery to replace the CQWP, but the only examples I’ve seen are pulling list items from a specific list on a specific site. Knowing little about using SPServices or jquery, I was wondering if this is the right path to look at before partnering with our developers to build a solution, or if anyone has a better path to look at.

Thanks in advance!