Do I have to be mounted on my legchair to use its support benefit and if I dont does it work at range? Is it limited to the legchair's melee reach?
Do I have to be mounted on my legchair to use its support benefit and if I dont does it work at range? Is it limited to the legchair's melee reach?
The mount trait doesn't require it. Neither do the Mounted Combat rules.
So no you don't have to be mounted on a LegChair to gain its benefit.
Curiously you don't have to be mounted on a Horse to gain its support benefit either. I suspect your GM may apply common sense though and rule otherwise here. I'm sure one of the developers made a comment about stopping players from using the bonus with spell attacks.
I'm not really sure of the additional benefit of the LegChair support option. AFAICT it only attacks from above that a normal mount won't provide you a lesser cover bonus against anyway. So allowing it to work dismounted seems right and appropriate to its description.