I'm back to looking at the event loop issue and now I can read old posts via gmane.
 I see Adrian pointed to this ancient thread:

http://sourceforge.net/tracker/?func=detail&aid=3028676&group_id=12997&atid=112997

in the comments of this thread das refers to a git repo where he did some experiments
because he'd decided Tcl_ServiceAll() wasn't doing what he needed it to. Does anyone
here know what repo and branch he's referring to? Has all this been imported into fossil now?

Cheers,
- James

PS Someone from sourceforge opened a ticket on why their forums don't wrap text...