Has anybody thought of _two_ TF disks, two different caster, each sitting in the others disk?
You should be able to travel well there.
The range is 25'+, so each caster just directs it to go 'there' and, viaola, you're travelling 25/round, 3' off the ground.
Personally, I would have a platform built and the platform placed on top of the disk to make it:
A) safer
B) more secure
Put in some high sides and you have cover.
Can you say Howdah?
Heck, the platform can be used with just one caster.
Each round the caster causes the 'Archers platform' to go ahead.
What think you all?
More later,
Vahktang