504 error during scan

Hello. I’m trying to scan my site using your plugin. About five minutes after I start the scan, the browser displays a ‘504 error’ popup message (sorry, no screenshot). Once I close that message, the scan seems to continue to run. Yesterday I let it run for ~24 hours, and it had made no progress. I then logged out of WordPress, and logged back in. When I re-opened your plugin’s admin page, the scan was still in-progress. But this time it was actually stepping through each of my plugins. After ~10 minutes, the scan completed. But the report was quite incomplete. For most plugins, it reported:

The plugin/theme was skipped as it was too large to scan before the server killed the process.

Full report here.

I tried a new scan today, and the 504 error occurred again.

So, thoughts on how to troubleshoot that 504 error message?

Thanks.

The page I need help with: [log in to see the link]