I will give my opinion, which I believe can constitute an answer (even though I am not sourcing any other information other than my ideas).
In the film Predators, we are introduced to the Super Predators that have a larger frontal lobe, swept back braids and are larger than the hunter-killers we see in the original 1987 film. These Super Predators stand at 7.5 ft tall. I believe that it is these predators that are partly-responsible for the advancements in technology and weaponry that we see in canon.
We obviously know that the Predators are divided into sub-species, of which these are but two, perhaps there are more variants that are totally responsible for design and build of flight-craft, weaponry and technology.
There is also an addendum to my opinion, that the notion that the species were responsible at all for the advancements in contrary to the fact that their visual acuity is not as advanced as (say) the human eye, that is, would the advancement in technology we see in canon be the 'preferred' solution if the species could only see in some range of the EM spectrum? that is, are the weapons and technology we see, advancements associated from a species who can see and develop arise from a species evolving like humans... perhaps the Engineers?