Back in 1996 Kings Island and Kings Dominion opened the world's 1st LIM coasters with Flight of Fear. 9 years later, (10 for Kings Dominion), Premier Rides gave both parks two more respective LIM coasters with the Italian Job Stunt Tracks. Once Cedar Fair bought the Paramount parks, Premier was never called back to do another ride. To this day Kings Dominion's Backlot Stunt Coaster was the last Premier Rides coaster ever to be built for a park that is owned by the Cedar Fair chain; none of Cedar Fair's legacy parks (CP, VF, KBF, DP, & MI) have ever even had one. 

I'm just curious as to why? Is there an exclusivity clause? Does Cedar Fair not like their practices? Do they not like their maintenance? It just intrigues me. Six Flags and Sea World entertainment have installed a combined total of 7 coasters from Premier rides with 4 of them being clones and 3 of them being custom launched layouts. 

Would working with Premier help or hurt Cedar Fair?

Well we all know that Cedar Fair has its favorite children, and it’s favorite children don’t have the need for a Launch coaster. That’s really all premier does, and if the favored parks don’t need an LIM/LSM, why work with them?

^ I agree.  Also there are the capacity issues that they have.

Paramount/Viacom also installed a Premier Junkyard coaster at C-Land.  

Maybe when CF took over, they were mad that Premier sold outdoor FOF clones, specifically at SFA, which is close to KD.

I think it's just as simple as there has not been a lot in Premier's portfolio that CF could not have gotten from someone else.

The launched coaster market is just so crowded nowadays it does not surprise me that they have not been compelled to work with Premier recently or anytime in the foreseeable future. CF built a number of launchers in the 2000s but none of those were really anything that would have been up Premier's alley.

That having said, I would not mind a longer version of Full Throttle, something like that...

It’s probably a combination of a lot of what was said above. Premier has gotten better, but in the past they had a bit of a reputation for less than stellar quality. Cedar Fair would rather go with B&M and drop the money now and save cost in the long run.  Their primary products like Skyrocket II are probably too low capacity for the big players but too expensive for the smaller players.

I feel like Sky Rocket IIs would be great at low investment parks like Worlds of Fun or Valleyfair that only see new coasters about once every decade. Heck Valleyfair added a Larson loop a few years back even though that's not a coaster