Hi Photon,
I guess the answer is who knows?
There are many around who have bought either cheap Chinese vcds clone cables or cheap handheld devices and have managed to get them working.
From reading much in the past, software based versions can take a good deal of time and knowledge to setup and then they don't support very much other than reading fault codes.
Most handheld devices tend to be able to read most controllers and clear any stored fault codes, but the one area all seem to struggle with is airbags, although I believe this is mostly to do with re-coding.
I have seen some youtube clips with owners using VCDS-Lite with a cheap lead and being able to read and clear stored fault codes, but I can't help with the type of cable or the source.
I would hope you'd be able to read and clear codes with most devices, but the best option is, obviously, a genuine VCDS, but at around £350 it's not always affordable. However I guess you spent a fair amount on the seats, so my thinking is perhaps you should have factored in the cost of a diagnostic device as well.
Hindsight is a wonderful thing, but I would always recommend scanning the car before commencing any work and then re-scanning once complete.....it gives great peace-of-mind.
Another really good reason for using a genuine VCDS is that if we were all to use the cheap copies there would be no money for R&D, Ross-Tech's application developers would go elsewhere and the product would end up fading away......pretty much as the outcome from any form of piracy (although I'm not preaching here as I'm not whiter-than-white).
I hope you get this sorted out and maybe someone local(ish) can help you out.
Cheers
Jeff