Okay, so trying to glean information form you comments to try to make a proper answer. Correct me if i'm wrong. So the question is a XY question. In that your asking for solving X but that's just the way you envision to solve the question.
Real solution
Now the real gist is that the thing your truing to get into vectors is already vectors just inside a CAD application. The primary reason is probably that you have no access to the CAD file itself or possibly lack skill in using said CAD application, which in this case is apparently Creo. Though you don't state of its creo elements/direct or Creo parametric.
Now this is a bit of a problem. It can be complicated if you dot have access to the file or if the file is structured a bit weirdly or its not a native Creo file. But also because engineers and the application use a different language when it regards to what you are asking for.
For reasons beyond the scope of this forum it would be much preferable to do this inside Creo if the program is Creo parametric, not only is it capable of doing this. But its capable of doing this for any conceivable situation you could encounter completely automatically after a initial setup in seconds and you would never ever have to do this again even if the model changes whatever the complexity. *
So I would negotiate with the engineering team about this. For the engineering team there is no more work to do a 100 grills than 1 once they know what they need to do and have a setup.
Could this be done in illustrator
Sort of yes. It would be a bit fragile and lot of work for ultimately something that would break if anything ever changes. SO while what your asking certainly would fix your problem to some degree. Its not easily possible. Why?
Well, the interpolation happens in the bezier t parameter space. A bezier is not linear as in the t does not increase easily understandably along the line. So any change in shape would also change how it tensions up. Fortunately you have the easiest iteration of the problem
So a solution was suggested that you use a 3rd item to adjust the tension. This works but youd be much better served with 4 items. Or by adjusting the spine of the blend (spine is the line connecting the blends). The spine is somewhat better as it allows for more degree of control. The spine can be adjusted just like any other spline. This can achieve and bend or adjust the distribution.
Image 1: Bent spine using anchor point tool. Note if you adjust the handles on a straight item it sill adjusts the spread but its harder to see as a picture.
But this is indeed a bit tricky to deal with.
Now if you don't like this there is a alternative option that you do then instead of a blend. What you do is you make a art brush, with a expanded blend. What you then can do is draw a line along one direction. Now you can enter into the brush and drag or arrow nudge individual boxes around. This is more like kerning.
Not sure its any easier.
And finally there is 3rd option draw a line like billy Kerr showed in comments. but make the line serrated then use pathfinder split and offset resulting shape inwards.
Finally
But yeah if i had the Creo model i would just do it in creo since its the least fragile option. Even if Creo sometimes sucks it does not suck here one bit, being probably the best software on the market to handle this particular problem sort of writing your own code which isnt that hard either.
Send this question to the design engineer, he will know what to do.
* Yes i would know how to do this. But it sounds like my day to day work in a way that i would expect to be paid for.
