While it is mainly a watch show, there may be opportunity to tie. It really depends on the tyer you are in front of, so make sure you read the room and the tyer. If you have some materials, bring enough for a pattern or two in a small, lidded tote... don't bring any more than that. There may be open slots, so ask at table location 1 or 2 and ask the Chairperson if there is a spot open.
I know this year, they were encouraging the scheduled tyers to bring a new tyer to tie with them at their location. You maybe won't find the classic salmon tyers promoting this, maybe not even the steelhead fly tyers, but there might be some trout fly tyers that will allow you tag along.