Hi
@Samuel Barnes and welcome
When you charge an EV or a PHEV, the maximum Kw charge rate is driven by the weakest link in your charging setup, being (a) the on-board car charger and (b) your Level 2 charger max output.
Most Level 2 EV chargers are usually a pretty simple and dumb devices, being basically a contactor (i.e a large electrical switch) to switch the 240V-AC On and OFF. The real charging conversion is done by the build-in charger in the Tucson.
The good news is, the Tucson has a very good build in charger at 7.2Kw. So this means that if your Level 2 charger can deliver (30 amps 240V AC) 7.2Kw, the charger in the car will be able to charge at a maximum capacity of 7.2Kw.
My personal experience is my PHEV Tucson often max out at 6.7Kw (27 amps) and never reaches the max being 7.2Kw (30 amps).
Tucson built in charger spec = Max 7.2Kw (@240V) = 30 Amps.
So in theory, for a 30 amp load (7.2Kw) at 80% load, the breaker should be 36 Amps.. Unfortunately, in North america, this 36Amp rating does not exist, so as per the NEC you jump to the next size breaker being a 40 Amp.
Since the NEC and the Canadian electrical code will most likely require to load the breakers at max 80%, this is why Hyundai specifies a 40 Amp breaker.
I own 2 chargers at home :
1 - Leviton Level 2 outside (4.8Kw);
2 - Bosch (7.2Kw) in my garage.
At work we have the FLO chargers and they are very sturdy, elegant and the cord is very flexible.
Honestly, Level 2 chargers are all the same IMO, unless you want fancy Wifi management software functions to track the Kw delivery and to manage charging times.
The thing to check is how bulky the cable is. my friend has a large Leviton 7.2Kw and the cable is so fat, its a pain to coil back for storage.
Stay away from the cheap amazon chargers, make sure you select a product that is UL or ETL certified.
Avoid chargers that have only CE certification since this is a crappy self certification.