insulated flex above insert install

[Benchwrench]

during an insert install is there a "rule of thumb" as to the insulation length around the 5ft. flex connection on top of an insert that the insulation should begin?
In other words can bare flex be acceptable above the appliance's adapter connector below the damper?
I'm wondering what the criteria is supposed to be regarding flex insulation just above the insert?

 

[stejus]

No need to insulate directly around the appliance connector. I would insulate everything above the blockoff.

 

[Benchwrench]

OK,
Wasn't sure about below the damper area.
Thanks a lot for the reassurance.

btw, I am taking pictures along the way during this install, will post them soon.