I think you could make a good star trek horror movie in keeping with roddenberry's vision of star trek, while also being genuinely scary.
In some distant future when a Hologram control computer can give you any type of media imaginable to within a 9.37% margin of error using available sources, and watch a Tarantino directed Star Trek, or if you wanted for some reason, a star trek directed by Tommy Wiseau.
Obvious spoilers, but the plot was like a nerdy-bullied gaming CEO would digitally clone his coworkers into a Star Trek bridge simulation where he would abuse them.
The digital clones had all their real memories and knew they were cloned into the game but had to play the part of a Star Trek crew going on adventures or be tortured.
i was thinkin more obrien & keiko getting lost in a black mirror/saw kind of situation where keiko has to cut out their unborn child with worfs foreskin to survive. more 'horror' less 'scary'.
edit: for the record, i didnt want to go there. he made me do it
... or why didn't some psychopathic Admiral decide to take the technology and crew an entire rogue starship with nothing by cloned Picards or a dozen ships all crewed by duplicated Datas or an army of cloned Worfs
If the transporter system is capable of disassembling someone or something at the molecular level .. doesn't that mean it would be capable of making a copy? There have been plenty of episodes where there were 'accidents' and duplicates were created. So it means that the system is capable of being programmed to make multiple copies if they wanted to.
And if that were the case, someone somewhere would have weaponized this technology. It's like the period when we all discovered digital music and duplication software and hardware became available, all of sudden we could duplicate any digital media we wanted and it went wild for a while. I'm pretty sure out of the billions of people and species that would have had access to this technology, one of them or a few of them would have put two and two together and figured out that it could create clones and duplicates. It would turn into a great weapon for someone with a maniacal plan.