I have both types of fuel containers and have never had an issue with either .The Honda accessory tank sits very nicely atop our Aluminess Box and is held in place with Cam Straps .
The Roto Pax is attached to the inside rear of the box as shown above in the post .
for Honda Tank
for rear mounted tank
Incidentally I would not buy the cheap copy of the Rotopax tanks offere by Koplin as they are Chinese and have issues with durability and leaking I went thru 4 brand new and never used tank's that leaked before I went back to the Rotopax units . I mistakenly thought that the Koplin was made by Rotopax .