remember that in the end of secret act 6 scene siffrin said that he made out of timeloop because of loop? so, it's NOT a lie, and it's not just a compliment. it's a bare truth.
just think about it. prologue siffrin (i.e. loop) did not tell thier friends about time loops. yeah, they said that they're not ok, but not about all the burden that he has on his mind. he still tried to process things all by himself. he was all alone, no one to talk about his feelings, no one to help him. so - he just gave up. he just had no other choice.
and now, think about ISAT siffrin. loop is here. siffrin can talk to them about all this, release their fears, cry about their anxiety. AND they have not only a person to talk to, but a person to encourage them! yeah, dude, go do that touch therapy with your friends. go tell them about loops. go talk with the king. go search every inch of the castle. go, do anything that comes to mind!
they encouraged siffrin to do not only things that they both did on their loops, but do ANYTHING. even things that was stupid, even things that was scary, or sad, or could make anything worse - all the things that loop themselves DID NOT do because there was no one to encourage them!
yeah, in gameplay terms you just talk to them before going to castle, but for a story it was A LOT.
loop really did the only thing that only they could do: helped siffrin to not give up.