The end of book 1 is when the channeling and reactions happen almost at the same time. After that he doesn't get the side effects of starting to channel such as taking chances, trouble moving his limbs, etc anymore and starts to experience the filth/taint. So my guess is a channeler doesn't feel the taint until they survive the channeling and side effects happening at the same time part.
Re-primary debates:
https://fivethirtyeight.com/features/the-dncs-debate-rules-wont-make-the-2020-primaries-any-less-chaotic/
Sounds fair?
The early (6 person) 2016 debates on the democratic side were laughable, but that's an aside
They are clearly motivied to have as inclusive a field as possible. The idea of multiple randomly-seeded debates isn't a bad one, but it'll make drinking games harder.
Something I've been thinking about post-Bernie entering the race, though this article is about Warren:
https://fivethirtyeight.com/features/elizabeth-warrens-ideas-could-win-the-democratic-primary-even-if-she-doesnt/
If the policies which are primarily identified with one candidate make it into the party platform, does it matter so much who's on the top of the ticket?
I'll allow that it does, clearly, but this is a question of degree.