You don't have to spend time researching or understanding a creature to summon it. Once you have seen a creature, and have sufficient mana you can summon it. You can summon multiple copies of the same entity from the Aether. You can even summon new beings you have created from the Aether, and even possibly create Eldrazi from the Blind Eternities themselves.
Time Spiral
Your ability to surveil other timelines and possibilities before planeswalking has allowed you to alter your summons, guiding them through speculative paths to emerge as another possible version of the same entity.
Invasion
Your creations are now able to traverse the Blind Eternities alongside you without succumbing to the detrimental effects that follow most non-planeswalkers. While this is the case, they are still extensions of your will, and cannot survive outside a plane for long without your presence and attention.
Conflux
Thanks to your understanding of the Spark, and its place within your soul, you can summon Planeswalkers from Aether much like any other summon. This is not a real planeswalker but an accurate enough summon to mimic their main tricks at the point you summon them. I.e. Jace was largely focused on illusions when he first planeswalked, but if you instead focused on his last form then madness and scheme would be his forte.