It’s been a while since I last played with a ZE20, Especially one of the Q models, but it won’t have been 43kW to the battery. AC Rapid charging is super inefficient so at full speed you’re probably still only looking at 36-38kW best case from memory.
I used to regularly drive a Q90 and the rapid charging was very much the same as the new ZE50 model even on AC. You had to have a very warm battery, and a very low state of charge. Plug in with 40-50% already on a cold morning and you’ll probably be getting less than 11kW for example. I’d be surprised if the Q210 was much better in these circumstances.
Either way, I would say it is fair. Especially on the Onto forums where they only offer a R110 or a R135. Both of them definitely do have strict requirements to get a decent charge rate.
(PS I don’t think it’s so much about the physical battery size nor cooling. Plugging in with a cool battery, or plugging in with 40-50% charge already would both be scenarios that would mean less heat that charging a warm, empty battery to full. It’s just general Zoe weirdness that slows down these scenarios… And the BMW i3 is an example of physical battery size. They went from 22kWh, to 33, and now 44kWh. If anything the charge speeds improved as capacity increased, despite doubling the energy density)