My simple approach to a complex issue :
I have put my mind at peace concerning the inevitable fact that my 'gauges' and 'effects' folders will become more and more bloated as time goes by. It's not a big deal considering the size of our HDDs.
Awareness of 'dll hell' has been with me ever since I first read about it - so I tend to be on the cautious side.
Typical scenario: I installed an a/c with 24 new gauges and about half a dozen new effects. A couple of weeks later I decide to get rid of the a/c - easy - but hey... do I remember which gauges and effects where part of that a/c?? Of course not!! Will this cause me sleepless nights? Absolutely not.
I just leave those gauges and effects in their folders. They won't do any harm.
Okay - yet another new a/c to install. And... again, so many new gauges and effects. I just go through the usual routine but when I'm asked wether to overwrite or not, I take my time and do the extra little bit of work.
I will NOT select either 'yes to all' or 'no to all' - instead I'll inspect each one individually and if it takes me all night.
Well, I said 'inspect' ... all I really do is just compare the dates and I'll opt for the latest one.
Friends, I do not claim that my method is 'correct' in a computational sense - but it's kept me out of trouble.
A final word for those still concerned about their folder sizes. Let's face it, should those two folders ever become so bloated that it seems necessary to reclaim some space on your HDD, it's probably time for a fresh install anyway, but, more likely, the next incarnation of FS has already been torn out of it's box and slammed into your DVD drive waiting to be installed.