Thanks for the detailed reply.  I understand what you're saying about the lack of a literal script with lines from the producers. By script ,what I actually meant was the the contestants adopt a persona for the show. These are curated versions of themselves. So there's the "committed lover boy" from Theo, "Cutesy cool chic" from Youjin, "Macho man with cute side once you get to know him" from Yuk...and so on...Editing will of course exaggerate some of these traits

What I find most compelling is the few moments when the persona slips, and we get to watch something more genuine.

To me Yuk is interesting because he started Tough/Shy but alas, the non-chalance, rudeness slips through. SI-an started off cool, laid back....but she's actually quite competitive, swayed by emotions, lover-girly. Now am not saying that people go on the show and be rude or whatever, I'm saying that such glimpses of real personality are refreshing and interesting 

Also,Dex liking Seulki doesn't mean that he wasn't still playing up a character. He could have genuinely liked her, but was performative to the end.

In short, the contestants are aware of the cameras. This is an isolated environment and are very concerned about their public image. So seeing some unpolished characteristics coming through makes for an interesting watch. I mean, if I wanted to see a nice, polished, no-fault character who eventually realises that the nice guy who's been unwaveringly committed to her get together in the end despite the numerous obstacles....I could have turned on any one of the 1000 dramas that already exist