Josh I too would like you to be a contributing member of the forum. You're obviously not a stupid guy, just uninformed. You were incorrect about a number of things and one for example is about the stock onboard calex charger. It does indeed operate by CAN. I'm not sure why you seemed to state with confidence it didn't when it does. And to stay within Zeros warranty any high power aftermarket charger does need to use CAN as well. The reason being that while the delta Q's can be simple "dumb" (vs smart, ill explain later) CC/CV since they are only 1 kW, the higher power chargers can not, because the charging curve can't run constant current at close to 1C all the way to 116.4v. Farasis noticed increased degradation when 1C charging at low temps close to freezing and also at higher SOC's. So they've updated their charging profile recommendation for maximum life.
I know Diginow has spent a lot of time to build protections into the charging profile by talking to engineers at Zero and Farasis to make it right. They are working on further updates even now. The charger you show in the picture is an old style "dumb" CC/CV charger that basically only runs 2 ways. Full power until it hits a predetermined voltage, then it holds that voltage and reduces current. That's how the "best" chargers worked a long time ago, and even my 1st generation Elcons did that on my 2012 Zero. But technology is improving and we are learning more about how to extend the lifecycle of Lithium cells greatly. One is by using "smart" chargers that run by CAN messages and listen to the bike znd no longer just do just CC/CV charging. They can listen and adjust current based on cell voltage, temperature or any number of things. Diginow is working on having current gen supercharger owners be able to swap out their control board to have Bluetooth LE connectivity to control many features to set charging to 80% overnight to extend battery life as well as adjusting current and load balancing between chargers to share the available power from say a single 110 source at 1500 watts between 3 chargers so they all run very cool or any setting you like. These CAN controlled features will make the bike happier, and make the user happier with more features.
Along the lines of reducing current before reaching CV I believe in the future Zero and Farasis will allow faster than 1C at lower SOC's. so basically a tapered charging curve that can be programmed via CAN messages to the charger to allow perhaps 2C or 3C charging at lower SOC's and taper to 0.25C before hitting constant voltage. This is how almost every major EV charges. As long as the cells are warm it can do about 80% in 20 minutes, and the final 20% in 40 more minutes. As you can see it's not equal power the whole time, and a CC/CV charger would not work to follow this curve and constantly adjust current.
Bottom line is you are correct. You absolutely can use those cheap "dumb" 2 stage CC/CV TC chargers as they are with a few cabling adjustments to charge a Zero and it will work. I used to charge that way myself. But now there are better and safer options. If you still want to use them you might be best to set them perhaps to charge to 110 volts or about 80% then reduce current a little or use some delta Q's or the onboard to finish it off. You of course can do what you want. But if in 5 years you have capacity loss on your cells, and Zero doesn't replace your battery, I wouldn't be surprised.
I look forward to another reply from you, and would love to hear that you got over excited and you didn't know some of the things I explained and just assumed you knew everything when you didn't. That's ok. You wouldn't be the first to do that. Here's a great example that will also lighten the mood a little. Jimmy Kimmel is great. It starts at 5:47 but you'll chuckle at 6:20. Basically it's ok to be wrong as long as you learn from it. That's what we are all here to do. Anyway go listen to Kimmel and put a smile on your face.
https://youtu.be/t16xYMSyMXU?t=5m47s