Packing Cube Backpacks Aeronaut vs Tri Star/Western Flyer

[Moose]

Hi All,
I have a Tri Star (steel & ultraviolet) in my future. I'd like to have a packing cube backpack too. I really like the one built for the Aeronaut because of the bottom zipper compartment. Is there any reason it will not fit in a Tri Star? From the size measurements listed it appears it would fit but I'm wondering if anyone has any experience with this combo. Any thoughts will be much appreciated.
Thank you,
Moose

[Just]

I believe that while the Packing Cube Backpack for the Aeronaut WILL fit into a Tri-Star, the issue is that it is not appropriately sized for the Tri-Star, as the Tri-Star compartments are lengthier than the main compartment of the Aeronaut. In order to take maximum advantage of the extra length for packing purposes, it is recommended to get a packing cube of the appropriate size.