Delco is a global company that supplies over 100,000 parts across 37 product lines - including Toyota, Honda, etc. (info from their web site)
The 10si alt is one of the most copied in the world. (info from an article I read awhile back)
I no longer have the box (which may have given a clue as to where it was made - maybe not), so I don't know WHERE the alt was made. I also really don't care. The price and design worked for me.
100% MADE IN AMERICA is a hard thing to find, anywhere, in many product lines. Who knows where the equalizer parts came from? Who really cares?
If the equalizer fits your budget and needs then it is the best thing for you. I'm the guy who will install some new 12 volt goodie and forget to turn it off leaving the battery dead. Knowing this I wanted my systems divided. If that's not a problem for the end user, or maybe they want to stay as bone stock as possible, then running dual alts may not be a way to go.
The delco alt on my 67 Chevelle has been there since 91 and been on four different engine/trans combos. I almost stole it for the deuce 12 volt project. No idea where it was made. Now that I have a core it's 30 bucks if I fry the alt. Everything else stays the same. You only get one shot to fry the equalizer, but most people don't have my kind of electrical bad luck so that's probably not an issue either.
In the end you just need to decide what works for you and go with it. There are several ways to run dual alts and there are many equalizers out there.