SO this is what you seem to be recommending.
(Its probably best to assume that instead of Tedesco - you are looping some other WFB that plays early in the round who you might not want in your 17. I'll leave Tedesco in there for now but in reality he'll always be in your 17 and you would probably want to try the loop on someone else)
15: 2RF (with no FRF DPP)
16. ?? (not 2RF or FRF)
17. FRF (with no 2RF DPP) - for arguments sake lets say Lodge
So with no changes, Lodge will go to FRF for AE and Teddy will slide into 17.
Moving Griffin into interchange in 14-16 won't change that. Lodge will AE for TPJ and tedesco will slide into 17, and you'll lose the score of whoever made way for Griffin.
Moving Griffin into 17 and Lodge into 19 means you'll lose Teddy's score and Lodge will be AE for TPJ
You could move Lodge to 21 and Griffin into 17, will get Kikau as AE instead of Tedesco - but you have to give up Lodge's potential score to do so. This is the main benefit being described. You get to see both Tedesco and Kikau's scores, and decide which one you want to keep. The potential backfire is that you have to give up the score of Lodge to do so (and can only score one of Tedesco/Kikau - if they both do well then you still have to give one up)
To do this you have to have a team of people playing the right position, playing games in the right order. Its not something you can reliably do every week.
Teddy is playing early enough in the round for it to work, it is all comparative to the other pieces you have that you can move around. Knights, Tigers, Broncos all play after he does, so its fine.
Sometimes it may mean playing someone in the emergencies that may not be what you would always have chosen, i.e. Griffin, but to me Thompson at Fullback against Eels should do just fine. In the case where we want to take Teddy's score, we are getting Griffins score anyway.
Another alternative is if Teddy and Kikau both flop with bad scores, then you can still get Griffins score instead in that scenario too.
My general philosophy is that if you can see the scores before making decisions on who to play, you have much better information than someone that doesn't and a much better chance of not getting low scores and capturing high scores of high variance players like Kikau and Tedesco who can both get 20 one week and 70 the next.
By having non-players in the 13, you get the chance to see 2 or 3 players play each week before deciding which to take. If your non-player is dual and plays late in the round, you get lots of options on how to do it. It has been easy to make it work for me on each of the 3 weeks that I have tried it, because I deliberately targeted a non-playing reserve that plays late in each of the first 9 rounds.
You aren't moving Lodge (or other original FRF starter that has been swapped to interchange), you are still getting their score regardless. You are just moving players to clear the way for the loop to work, as it doesn't work if you have lots of duals in the interchange, like Rochow. The other advantage of Rochow in the starting pack is that he becomes interchangeable with TPJ to be either a FRF or 2RF, as both play at the end of the round.