I'll reiterate my original remark that it would be worthwhile tracking down and fixing the virtual memory or paging bug in sources plan 9,
not necessarily to make use of paging, but to ensure that the paging problem isn't just a symptom of something else that normally gets by.
If 9front doesn't suffer from it, that must help to narrow it down. (I thought the relevant virtual memory changes from 9front were in sources, but evidently not. There are so many variants now I've lost track.