You could also replace the boot with a shorter transition boot like the one pictured here.
This one goes from a hood outlet to 7" round (but can also be found in other sizes). That would leave you pointing straight upward and save you a turn rather than having to 90 directly off that HVAC end boot that you linked which looks more like what you'd find on a floor or ceiling register.
I find these parts are usually sold in the kitchen section of the big box depot rather than with the rest of the HVAC ducting.
I see in the attached photo that there is already a transition to vertical round duct. In that case, I'd just try to shorten that crazy straw as much as possible with snips and foil tape.
You can cut back the stub sticking out of the wall to give yourself additional room. Just leave enough stub to get tape and a band clamp around.