The difference in (in what you are asking) is, the Gen 2 wall connector has a physical dial that you set, to set the charging amps. The gen 3 wall connector does it via software during its commissioning process.
There may be some AHJs (authority having jurisdictions) that may not like the fact that the Gen 3 is set via software, so some localities may be requiring gen 3s to be on 60amp circuits because thats "the max" and "what it comes set to out of the box".
Electricians also do not tend to like the idea of setting something like that via software as many dont understand (or trust) it. The gen 3 wall connector does not "require" a 60amp circuit as far as setup goes, it just has to be configured for the load the same as the gen 2, but has the stipulation above, of being configured via firmware.
If I remember, you are (or were) an IT person, so configuring something via firmware should be a familiar concept to you. The thing is, does your local AHJ accept it for gen 3 wall connectors or not? It can be "rip N replace" for what you have, you just need to set the amps in the firmware.
Or, alternatively, get a gen 2 like you are asking for, where its set via dial. I happen to prefer the gen 2 (its what I have, and I went out of the way to get another one to pair with the one I have for power sharing), but Gen 2s are getting rarer and rarer, and people with them are sort of in that "I know what I got" mode. People who prefer the gen 2 for its higher potential capacity (unnecessary in modern teslas) and better build quality, and ability to power share via a cable vs wifi setup, are generally also willing to pay more than these were new to get one.
TL ; DR -- Gen 3s can be set to a lower amps through firmware, while Gen 2s set it via a physical dial. Your AHJ may not accept lower settings on a gen 3 because its a firmware setting. Electricians may not like the fact its firmware vs a dial, but thats how it works on a Gen 3.
