Insulated transition for roof terminals?

[LinearPancakes]

We're looking at using the Lindab VHL and VHA roof terminals for supply & extract respectively.

 

The MVHR unit will be located in cold loft space right underneath where the terminals will go, so only short runs needed for intake/exhaust to outdoors.

 

Most of the time the loft should be a similar temperature to outdoors, but probably getting hotter in summer. Based on previous advice we're looking to insulate those runs anyway, I guess primarily to avoid heating of the supply air, rather than to avoid condensation.

 

What I'm wondering is, is there much point having insulated pipe continuing through the roof transition to outside. I can see the benefit if you've got a warm loft, as you don't want the cold bridge and associated condensation risk. But if the loft is usually the same temperature-ish, is it worth it? I'd prefer to have the smallest hole through the roof we can get.

 

Lindab diagram below. Specifically we're talking about a 160mm duct from the unit and possibly up to a 280mm diameter transition piece if we went for their SRIP, that does also handily match the terminal diameter.

 

Thank you!