Even after getting rid of any Session variables, I was still having disappearing data, so I did some more digging. Apparently recycling is not the only problem (although once a minute does cause the Scheduler lots of heartache). On all page updates, the _view_state is empty. To see if I could duplicate this, I turned off view_state in IIS Manager. Even with view_state set to False, I get SOMETHING:
<div>
<input type="hidden" name="__EVENT_TARGET" id="__EVENT_TARGET" value="" />
<input type="hidden" name="__EVENT_ARGUMENT" id="__EVENT_ARGUMENT" value="" />
<input type="hidden" name="__view_state" id="__view_state" value="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" />
</div>
But when I get a page from my host, I ALWAYS get this:
<div>
<input type="hidden" name="__EVENT_TARGET" id="__EVENT_TARGET" value="" />
<input type="hidden" name="__EVENT_ARGUMENT" id="__EVENT_ARGUMENT" value="" />
<input type="hidden" name="__LASTFOCUS" id="__LASTFOCUS" value="" />
<input type="hidden" name="__view_state_CACHEKEY" id="__view_state_CACHEKEY" value="VS_5sjxwfesvgzpru2meebp1f55_633841950438252352" />
<input type="hidden" name="__view_state" id="
__view_state" value="" />
</div>
So it LOOKS like the view_state is being cached on their server - but the cache is getting wiped as well. But I thought the ability to cache view_state was in MY hands, through web.config and DNN core code? Guess I'm not as smart as I thought. Of course, now this probably doesn't fit in this group anymore, but I'd love any insight into what's going on here.