Plugin breaks on installations with many users

I run FeedWordPress on a site that has more than 30,000 registered users and authors.

Unfortunately, the page to select and administer authors within a feed at FWP breaks when I visit a link like this:

mysite.com/wp-admin/admin.php?page=feedwordpress%2Fauthors-page.php&link_id=22

I have temporarily increased my CPU on my VPS to incredibly high limits, but that page still breaks. I also increased the PHP loads, but it times out too.

I think the problem is because FWP tries to create a dropdown list of all the possible authors. So the solution for installations with so many installs may be instead to use an Ajax-based “user discovery” textfield. But that may break too.

Any ideas on how to help fix this? Even manually is there a way you can suggest I fix this in my version of FWP?

https://ww.wp.xz.cn/plugins/feedwordpress/