Since I already have the Tesla 32A Mobile Charger, 40A would be a requirement. I currently live in San Jose. Typically, I'd agree with you: 32A is enough at my home and local drive. However, when I arrive or leave (or stop by) my parent's house in Los Angeles, I can use all the charging speed I can get.
Well again, there's nice to have, and there's necessity. I'm assuming that there are a few Superchargers within reach of your parent's house (or en route). I suppose maybe you are trying to save some money and time by avoiding using a Supercharger, but several hundred dollars worth of 40A EVSE is going to get you more than a few Supercharger visits!
When I visit my son or in-laws, I am stuck with 120V, and my in-laws in particular are extremely far from the nearest Supercharger. On my last trip I arrived at their house at about 6pm and had to take a 90 mile round trip excursion the next day at 7am. Sure, it would have been nice to be able to start the day at 100%, but really it wasn't necessary. I just had to plan for that trip and stay at the preceding Supercharger a bit longer than necessary en route to their house. Sure, I probably paid a few bucks extra (turns out the time didn't matter because by the time I went to use the restroom, which was a bit of a walk away, the car had plenty of charge).
Of course that's my situation...everyone's is different.
I was eyeing the Clipper Creek stuff. I'd likely get their dual charger for my home (San Jose) in the future to accommodate my girlfriend's future plug-in Hybrid. However, I want something more "portable" at my parent's house.
Once again, you should consider whether you actually need this or not. Of course you will need a J1772 solution for the PHEV regardless, but speaking from experience (there have been two EVs of various types in my household since 2013), and current owner/user of a dual-headed EVSE (not Clipper Creek, but rather a homebuilt one), we very rarely, if ever, actually need the dual-headed capability.
Our first experience with two EVs was when I had an old LEAF (3.3kW charging) and my wife had a 2013 LEAF (6.6kW charging). Both needed to charge every day. She would plug hers in after work, and it was always full by 9pm at which time I would go plug mine in.
Then she got a Volt which only had 3.3kW charging and despite the smaller battery, was a real slow poke to charge. There were some days when she came home late that it wasn't done before bed. This is when I built the dual-headed EVSE, which was the only time we really needed it.
Eventually I got my Tesla, and she got a Bolt (and now an ID4), and we still use the dual-headed EVSE, but not because we need it (we almost never do), but just because it's the only one we have. Because we typically don't need to charge our vehicles every day, we can easily plug hers in one day and mine the next. I typically plug mine in when I get below 100 miles of range, but given that I don't put that many miles on a day, if I get home and she needs to plug hers in, I can always just wait until the next day to charge mine overnight.
I don't deny it's nice to have just in case, but it would be pretty hard to justify buying a $1000 unit these days when we would almost never use it. Long distance EVs have changed the equations here. Again, everyone's needs are different, but I would ascertain whether you really need it or not before taking the plunge. Sure, a PHEV is definitely a different beast. It probably needs to be charged daily, and if you do so overnight, it definitely consumes the charging station/outlet. But is a dual headed EVSE what you need, or maybe just a second outlet? Something to consider.
