This ^^^
I find getting the blueprint part to be very cool, first time I went there I absolutely loved it, it truly felt like an xeno-arquelogy expedition, in a very eerie setting. Precisely the kind of thing I always hoped to get from a space/scifi game. But getting some of the requirements to actually use the blueprints is quite a bit of a pain, more precisely the obelisk scans. Each guardian structure has less than a handful of obelisks (5 IIRC), and several blueprints require over 20 obeslisk data of specific types. Of course, I could do a relog marathon and farm thoss 5 obelisks for hours, but what crap gameplay is that?..
IMO, the best implementation would be each guardian site having it's own distinct blueprint, AND all the items you would need for that specific blueprint. Alternatively, there could be only the blueprint, no additional requirements and make it more difficult to get the blueprint.