The code requires a disconnect for installs at the service. The conductors and switch will be sized at 135% per article 460. My primary concern is that the 480volt switch gear is full. I suppose, I will have to add lugs to the switch gear and employ the tap rule to mount a regular old 480V fusible switch. Are you saying this type of switch won't work?
The code requires a method to drain the cap bank. I assume the caps being proposed will have resistors built in.
My one line is too simple: 480v gear----------fusible switch---------cap bank. I won't know how many kvar until the engineer tells me.
As a former applications and sales engineer I learned to approach providing answers to questions very cautiously. Very often if I provide an answer when I don't know the real application my answer can be applied incorrectly which can be dangerous.
Yes, the caps do have those drawing resistors in them but the is time between them being disconnected until the voltage drops to a safe level.
With your application it appears to be straight forward. You described your arrangement as swgr fused sw caps. As simply described you are coming directly from the swgr bus to the fused switch to the caps. Where does you cable originate from the swgr and what protects the cable or are you considering the cable under the tap rule. I've been concerned with the disconnect being able to disconnect the cap bank while it is energized. This may not be a problem at all but I think that you will agree that this is not a common application for a disconnect switch. How it would be fused could be another question.
Those who have not appreciation may just through a fused disconnect in there with out giving it a second thought but is it a correct application?
The question that should be addressed is if the disconnect switch that you have selected capable of disconnecting the energized capacitors. I would like to think so but I would certainly ask a person who has knowledge of the switch and how they would be applied with as a disconnect for energized fuses.
Then there is the concern with the access to the caps if they have not completely bled down after the switch has been opened. And what prevent access to the cap until they are completely been de-energized.
There may be a very simple answer but you're going outside the box a bit and what you would like to do I believe is quite reasonable. But also CYA.