Okay, lets get this down to the ground a little.
First thing, Mountain_Kat, I agree, the GB4 site is a trophy case or the term, I used garden. The problem is, that this exactly documents, those dead girls have actually a post mortem meaning for him. Not as individuals mostly, but as trophies. And as it is for most people, who collect trophies, the collection, the number of trophies in it is the significant point in having a trophy collection in the first place, especially in the case a trophy collection doesn't contain special singular items but heterogeneous items or in this case girls.
Now the point here is, this dump site wasn't in a really remote place, it was along a road. Roads always bear the risk, someone uses them. So it's not the kind of place, an SK can sit around for hours to relive what he did. And it's for sure not the place, he can commit necrophilia. So, when LISK dumped the first body there, then the second, he was aware of those limitations. It didn't bother him. That tells me, he doesn't need to sit there for long times, he doesn't need to touch or watch them regularly.
The other part to that, is something I told a thousand times: There are SKs who keep bodies or body parts. If so, they do it in a place they have control over. Their own places. On the other hand, SKs, who build clustered dump sites, they don't do it just a mile away. To my knowledge, Corll is the one with the shortest distance between home and dump site on record: 17 miles. Record holder is, as far as I know, Bundy with about 120 miles. To have distance between home and dump site is not only forensic counter measure. SKs who build such clustered dump sites chose the places carefully for their needs. A Bundy in his Washington State time, he picked places in the forest, he felt as calming, peaceful. Corll picked his two big dumping grounds because of the combination of forest and water which he felt as peaceful. To drive out to such a clustered dump site is special and has to be special for an SK. The trip has almost ritualistic significance and it is the anticipation that makes a big part of it. Therefore, I don't think, he lives nearby or his daily routines lead him pass that area. That would be too mundane, not special and therefore not significant enough for him.
Second thing, Dormer in that docu. Well Dormer tried some four months to convince everybody there wouldn't be an SK at all. Since then, he tried everybody to convince, there is only one, despite the obvious differences. Dormer has in the whole story said nothing beyond the fact of the body discoveries anything, that would display any kind of brilliant thinking, understanding of the situation or an interest in anything else but to survive the time till his retirement. And while I don't think, SG was actually murdered, one has to admit, his line about, she ran off and drowned was more a lucky guess than based on knowledge. So, why would anyone try to base know a significant part of a theory on something Dormer said. Not even on a complete sentence but on single words picket out of the mess without context?
Third thing, LISK: Most psychopaths are not only pathological liars, they are pretty good at it. And the higher IQ types of psychopath learn already in their youth a lot about emotions. Because people always expect some kind of emotional response from them, a response they can't feel, they learn to figure out what is expected and fake it. Now, people don't think too often about it, but there is a second side to this ability. They often can with the same technique figure what other people feel, what emotional response to expect from them. They can, especially if the person they talk to is young and vulnerable, manipulate them. Thus, a psychopaths behavior in such a phone call is goal oriented, it is not what he feels, it is about what the called person feels. Aside of it, we know, those calls are not actually part of LISK's ritual, nothing, he needs. He made such calls only in one case. So either, there is something very special in that case for him or the calls fulfilled a purpose. Now, if a pathological liar with the ability to foresee emotional reactions in a 16 year ld girl calls her, what will he use as tool? The truth, that will maybe lead the police to him and that will give the sister a first sense of knowing, the victim is dead? Or another version, one including hope for the price of ongoing terror with the additional advantage, that he can lay out whole boxes of red herrings for the gullible? Which way would a psychopath chose?
And aside of that, to hold a victim for a time longer than maybe three days, one has to be unemployed or on vacations, needs a very private place and more important accomplices so one gets a little sleep in between.