I attended ERScream. I thought ACE put together a nice event and made the best of the way things turned out with the weather. 

For what it's worth, ACE held an event (ERScream!) at KI last October.  It seemed well-attended, but the weather was poor.  At dinner in the picnic grove, park manager Tony Carovillano announced the park would be closing early.  This was a bummer and meant no haunt attractions, but was understandable due to the weather.  Overall it was a good event with a slightly disappointing ending.   I was looking forward to KingsCon as a follow-up event, especially with the uncertainty about Coasterstock this year.  If they do have Coasterstock, I wonder what the price will be.    

Edit.

Again not sure what happened 15+ years ago at the park that obviously some people still have negative feelings about but I can say that the park was noticably more likely to work with enthusiast clubs while @DonHelbig was with the park especially compared to their current leadership. I think ACE and GOCC and other groups have had issues with their connection with the parks disappearing as people like Don move on or get replaced. The relationships are no longer there and Enthusiasts are treated the same as a company like P&G or GE or Kroger trying to rent out space in the park. Traditionally enthusiasts were often given special privileges and pricing and the new leadership doesn't have good relationships with the club representatives therefore organizations like ACE get treated the same as any large cooperation - if you can't put up the money or the numbers to meet the minimums the park is not going to do anything for you anymore 

True, but if they are in a contract to use the current IPs and Six Flags branding, I'd hope they would not remove it and have a clause to move it post season.  If I were in Enchanted Parks management, I would seriously think about dropping any six flags branded item in legacy six flags parks.  St Louis would be a challenge because it's always going to be called six flags by locals.  That's going to be mighty challenging to switch the parks.  Uniforms, signage, ads, vehicles, SOPs etc.  It would be a perfect time for WOF to change the sound of their in park cartbulance to a siren from one of their worlds.