Just think of "full spectrum" as "all ingredients present", sort of.
That means fullest spectrum would be grinding the seeds and flush it in, some people do that but it gives the most burden on the digestion system that gets to process it all.
Second in line is making a tea from the (grinded) seeds. Drink that tea and a lot of the plant material is saved out on the digestion system. Bad taste but you get a very wide spectrum ingested of everything that is water soluble.
Third in line is making the tea basic (like adding lime or calcium hydroxide) and a lot of the elements will become solid and settle at the bottom, discard the liquid and have the sediment as your extract. Often the sediment gets flushed with water to flush away the basic medium (especially necessary if one used lye to make basic).
Fourth in line is dissolving that sediment in an acid watery stage (like with vinegar) and adding kitchen salt (in the right ratio's) and some particular harmalas will now form solid neddle type precipitation. Keep those, discard the liquid, now you have the HCl form.
So you see the HCl form is furthest away from the "full spectrum".
Except from eating seeds material, all is an "extract" to some level, and going further away from "full spectrum" your extract gets narrower toward certain constituents of the original seeds. No one approach is best in general terms, it's just what are you looking for? Some people are after max plant material medicinal properties, while others are after lesser burden on the digestion. Some are even interested in dividing the HCl form in it's 2 main alkaloids Harmine and Harmaline and separate those. To each his own game.
I hope this answers your question
. . . is there REALLY no way that a real harmaline/harmine extract can be full spectrum??
Check out the harmala extraction teks in Wiki to see it happen in details.
Cool