That is not how the Shulgin rating scale works. It is first and foremost dose-dependent, but also related to set and setting. There is no list nor can one be made of tryptamines which are ++++, as it is the individual experience and moment which is given a rating, applying only to that particular experience as a unique event.
A ++++ is a unique transcendental state and there are no drugs which are guaranteed to induce it. Very high doses of plenty of psychedelics - probably most, I would say - will reliably produce a Plus Three eventually. Then I would say there's a few that stand out in that they reliably produce Plus Three states even with conventional, non-heroic doses and are more likely to result in Plus Four.
N'N-DMT, 5-MeO-DMT, and DPT immediately spring to mind, as well as psilocin to a slightly smaller degree.
