Need to crawl over newly blown insulation

Rather than crawl over the insulation, lay boards across it from beam to beam.

Blown on insulation hardens pretty quickly . I don't think you'll have to fluff anything .

Use a plastic fan rake. Take some boards up there to make a path over the joists to your window. Then use rake to fluff up.

As a precaution I would recommend using a face mask just in case.

lay boards across your beans and walk on them. That stuff will make you itch badly for days if you crawl on it and be sure to wear protective clothing, a respirator (not just a paper mask which lets those fine particles of glass come in around the mask as you breath), gloves and eye protection! This stuff is nasty if you get it on you, breath it in or get it in your eyes. Better safe and uncomfortable opposed to ending up at the doctors office or worse.

If you can, gently part the new insulation on the path you need to take to do the work and use cardboard to damn it back. Once done, from your work point, release the barrier and "fluff" from the bottom up with a kid's rake, hair dryer on cool or even something like a tennis racket. Since the insulation won't be compressed, it should fall into place just fine.

I had to repair a kitchen vent pipe that went through the attic. Also have blown insulation above the joists. Laid down some plywood boards where I needed to go. Once I was done I just fluffed it up with my hand. Wear eye protection, dust mask, and gloves. Doesn't really itch but is messy.