Can I put a "U" turn in my range hood exhaust duct?
The person that told you grease will collect there was correct.
The other issue is each bend creates flow restrictions reducing the flow from the blower. Everything may work fine with 1 or 2 elbows but 4 is beyond the norm and your hood may not work well plus the built in grease trap.
I would try and lower the hood 4” and box that in it may look “different “ but a straight run until you can go up would be a better plan.