How do I mention practices about raising PRs within this dev’s performance improvement plan?

Hello, there's a dev I work with that hasn't been meeting expectations in a lot of areas. One of them involves PRs. He'd consistently raise a PR right before standup , the PR would have lots of bugs and the reviewer would have to sort through his code. It's become obvious to many people on the team that he does this to have an excuse to be "checked out" for most of the day.

How can I phrase some improvement plan point concerning this? Saying "Don't raise PRs if standup is within 1.5 hours" seems too general and doesn't really speak to the fact that the quality of his PRs is lacking. He has also raised multiple PRs and if something is failing he would change two parts and raise another PR. (while failures are still happening) Any feedback on how to rephrase this to set clear expectations?