I have a very odd and convoluted path for running an exhaust fan for a kitchen.  I love solid vent pipe and would love to figure at way to use it but …. man …. not sure I can .  Can I use some flexible duct?  Is there any issues to be aware of??

My configuration, if I can explain, is:

Stove on 45 degree interior wall.  So I can go up with retangular duct.  If I use a rectangular elbow teh vent will now be directed at a 45 degree angle to the floor joists inwhich I need to run the vent horizontally.

From that elbow I suppose I could convert to a round vent and use a 45 degree adjustable (elbow?).  Then run horizontally toward teh exterior.

However, I have a can vent in the bay with 4 inches of clearance above it, so a 6 inch round duct is no good.

Ok, say I get to the outside wall.  At that point I can come out into my roof overhang.  And I mean IN it ( have 2 x 12 rafter tails and the vent from inside the house would be more or less inside the rafter tails.  AND I have an intersecting roof coming into the roof overhang in which teh vent dumps.  So I need to do one more 90 degree turn within the rafter bay and perhaps dive it down a bit to some kind of a termination.

So if I could use flexible ducts it would seem to be easy enough to run verticlely from the hood , convert to round ducts attaching flexible ducts and snake that all the way to the outside.

Am I missing anything?

What type of flexible duct would be best for this application if at all.

Thank you all.