How did the issues I wrote in the previous post turn out? Well, Dataprobe shipped the iBootBar back promptly (two day turn-around at their end which I suppose is reasonable) with the settings reset, and with the new firmware that now has a hardware-based password recovery mechanism. The project was delayed by a few days, but such happens. I’m ok with that and will buy and recommend Dataprobe products in the future.
Meanwhile Adaptec could not (or would not) find the drive activity LED cable. I also found that the “kit” for AAR-2410SA is simply not just the card with more software and cables—it’s the controller with a drive enclosure kit at more than three times cost of the controller by itself! So if you install 2410SA to a chassis without Adaptec’s enclosure kit, Adaptec has decided you don’t need to have a visual cue as to whether the array is active. Adaptec clearly suffers from the »large business syndrome» where customers aren’t always accommodated, even if they’re willing to pay. Individual end-users are not significant to the bottom line. 
I’ve also been trying to source the connector, but so far the attempts have been fruitless. A picture of the cable shipped with the kit can be found on this page. Below is a picture of the [male] connector on the controller itself. If anyone happens to know where to find a cable with such connector (Adaptec says it’s “not proprietary”.. but clearly it is not very commonly available), I’d like to know. It doesn’t matter much what’s in the other end of the cable as the right kind of connector can be easily attached with some solder.
Since the controller supports four drives and there’re four pins on the controller, I assume each pin, representative of a drive, provides +5v to a corresponding LED with ground being supplied from the PSU.
The problematic drive activity LED connector on Adaptec AAR-2410SA. The female connector that would match the male connector on the card would be about 5.6mm wide.