That's why PR should be small. It's much better to have multiple PRs than a single big one.
Totally fair to have gigantic PR full of boilerplate code, but generally you can split the boilerplate and your feature in 2 PRs, where only the feature will get a proper review.
All of this obviously depends on the criticality of the system :p
That can lead to another problem though, which is that if a developer knows a merge is only part of the whole change, it becomes easy to assume any issues will be handled elsewhere.