Oh we have single axle trailers as well.. nearly no small trailer has a dual axle..
My concern is exactly said tilting on the axle...
No, that might be the wrong word again..
I'm perfectly sure, that you KNOW what you're doing,
it just looks odd to me considering...
the tow bar will be high up when the tank is just at the back of the trailer..
and in my mind it'll lower rather violently when you move the COG past the axle because of the weight *shrugs*
But I'll wait for the video to make my final call
'sid