At this point, I don’t think it matters. The important thing is keeping your training low intensity rather than specific. Later, when you’ve fixed your ADS, then your high intensity training should be specific. But right now, do the type of training that you enjoy the most and/or mix the two for variety.
And as far as being able to run uphill under AeT, it depends on the grade. In a skimo context (with grades of ~25%), the pros only run during a sprint race which would be a ~4′ maximum “VO2” pace. That’s way, way above AeT. Long course race pace is well below sprint pace. And AeT pace is well below long course race pace. Basically, having to walk up steep hills to stay below AeT is normal.