with aspect patterns I tend to focus on physical bodies… planets and asteroids. For example a stellium is 3 or more planets in conjunction (personally include asteroids). So if you have lets says 2 planets and the north node conjunct that’s not a stellium… but if you have 3 planets conjunct + your north node, well that north node should be considered as part of that stellium… and the same goes for other mathematical points. Another example is what if you have 2 planets conjunct your ascendant? Would you consider that a stellium? So these mathematical points can be a part of an aspect pattern but don't necessarily create them. The reasoning is that planets in aspect affect each other… but these points such as the ascendant & north node only receive planetary energy. Example from my chart is that I have Neptune sextile ascendant… my Neptune will color my ascendant, but my ascendant will not do that for Neptune :-)