The change at https://chromium-review.googlesource.com/c/infra/infra/+/1378746 limits the number of requests to Gerrit by always only requesting a certain number of changes in one request.

It still leaves the number of polls to Gerrit at 1 per minute for each LUCI project; another change could be made so that the poll-project handler adds another task to the task queue with an offset if there were more results. That should help make it so that no changes are skipped, but if a burst of hundreds of CLs suddenly comes at once, they will be handled at a rate determined by the task queue rate.