I've found that using IWYU Pragmas [1] for codebases you own and IWYU Mappings [2] for third-party libraries __almost__ entirely eliminates weird IWYU suggestions (there are a few annoyingly stupid suggestions from the tool I just ignore).
I've also recently been making libraries I write compatible with users that run IWYU by annotating all public headers with IWYU pragma comments that export symbols/transitive includes correctly, etc.