We've figured/figured out a lot about how ...

[WilliamTaft]

Charles Darwin and Alfred Russell Wallace were the first to put all of the pieces together into a unified explanation that would radically alter our understanding of life on our planet.
But our understanding of evolutionary theory didn’t stop there.
We’ve learned a lot -- and we’re still learning.
In the last 160 years, we’ve learned what Darwin and Wallace didn’t know, and we’ve figured out a lot about how evolution actually works - like how it can produce the incredible array of animals you see here, and how we know they’re all related.

Source: How Evolution Works (And How We Figured It Out), PBS, YouTube

The Britannica Dictionary
figure
2 US, informal
a [+ object] : to understand or find (something, such as a reason) by thinking
figure out
1
a : to understand or find (something, such as a reason or a solution) by thinking

Does "figured" work in this context?

 

[SoothingDave]

The figuring is in the past. So, no.

 

[Tarheel]

We've figured it out - We've worked on it (in our heads), and now we understand it

I hope you know what "figured out" means now. If not then you still need to work on it some, don't you?

 

[emsr2d2]

We've figured out a lot about how ...
We've figured a lot about how ...

Note that the phrasal verb can be split, leading to:
We've figured a lot out about how ...