There isn’t a list because its different depending on region, speeds, ISP, etc. 

so you won’t find a list. 

the firmware is part of the provisioning for your service so will be current for what that ISP has approved for you

So there is no way to determine if the Firmware is up to date with the most recent version then? Because I called my ISP, Xfinity, and they were clueless when I asked them to check to make sure the Firmware is up to date. 

The reason I'm looking into this is because of online gaming lag/latency issues. 

The firmware will be the latest approved by the ISP. 

What are you gaming on? 
Over wireless? 

Wired? 

What game? 
what is your latency when tested?

I'm on a MSI Stealth G77 gaming laptop that's less than a year old, over wireless and over a CAT 7 cable (which made no difference via cable or WiFi unfortunately), Diablo 4, and my latency ranges from occasional high 40s to 70s msec which I can watch live in game. Lately my latency has been in the 60s to 70s plus which is not optimal for online gaming. I'm rarely seeing 40s msec lately, I'm mostly seeing 60-70s and up. 

Is it the same in other games? The latency can be depending on what server you’re connecting to and if the server is quite a ways away, it increases your latency

I'm not sure. Diablo 4 is the only online game I play. You're automatically connected to the closest server in the game. You can't change which one you're connected to. I'm probably just going to try a Xfinity router. 

 Normally, service provider must distribute firmware updates to cable modem devices.  

 ARRIS develops the software update and makes it available to service providers. 

The service providers qualify, test, and distribute the software update to devices on their network.  It has limited control or visibility on distribution by the service providers.

Thanks. I called them and asked them to check if the most current firmware version was installed and of course the technician had no clue what I was talking about. It's funny, the lag/latency has gotten better since I forced them to do a service call to my house, even though all their technicians kept blaming my non Xfinity router.