Large numbers of comments added to a page seems to add outsized weight

In troubleshooting, we discovered that on an instance in the wild, pages that had hundreds of comments on them performed substantially worse than other pages with similar page weight, but less comments in a proportion that far outstrips the additional weight that the comments might add in simple page volume.

We found that in this environment, pages without comments, the domContentLoaded event was being thrown 1.5-2.4 s in, whereas a page with large numbers of comments could take 8-10 seconds.

When creating a blank page in a controlled environment, I added 1k commentors and tried to access this page with a non-superuser.

Regardless whether the comments were all made by a single user, or 1k different users, I was not able to get an appreciable difference with regard to the speed, nor did I feel that the performance penalty was outsized considering the added page weight.

The customer in question where this strange phenomonon can be seen does have a very nested architecture (based on ldap nests + crowd) so it is possible that there is an interaction in the customer system that would not appear in a testing server.