To my understanding, to make SMP loops work you need to use ten moves that have a repeat proration value on them in one combo before using an 11th that loops into itself xN. The fact that they're different moves isn't a necessity in activating the "glitch", but if you were to use one of the moves with SMP more than once in that combo, it would apply the penalty and make you drop the combo. Therefore, since 4B(2), 6C, Cavalier, Sickle Storm and Crescent Saber are the only moves Lambda has with repeat proration, an SMP loop with her is essentially impossible; there's no way we can use ten SMP moves without using at least one of them more than once.
This is why you often see more than ten moves being used in a combo; some of the other moves don't have SMP and therefore won't contribute to the total. I'll use Noel as an example since I'm most familiar with her. The moves Noel has that have repeat proration are 6C(2), Optic Barrel, B Silencer(1), C Silencer and every one of her drive moves making for a total of 23 SMP moves which makes it very easy for her to pull off SMP loops. Any other moves (6C for example) that are used is basically filler material to get to the next SMP move (6C > OpticA, 6C > B Silencer etc.) and doesn't actually contribute to the SMP total.
Since gold bursts don't have repeat proration they don't count towards the SMP move total, but they do have the bonus proration and can help lengthen SMP combos in the same way that they for normal combos. Once the system starts ignoring SMP, the only thing that stops the combo from being an infinite is the fact that hitstun deteriorates as the combo goes on allowing them to tech out eventually.
So yeah, that's all I can add on the SMP front, but the TL;DR of it is that an SMP combo with Lambda just won't work.