There have been some wondering if carrier compatibility (USA “big 3” carriers in this case) for iodé supported devices could be listed in a table. Before considering creating that, I think it would be good to make a few notes for people wanting to confirm if a device they purchase will work on their current carrier network (for voice mainly, but also for data).
TL;DR: make sure the device supports LTE, is a “carrier unlocked” variant, is NOT the “Verizon” variant, and is from a manufacturer that supports unlocking the bootloader. Use swappa.com as a reputable reseller.
Longer explanation:
I’ll abbreviate the networks as V as Verizon, A as AT&T, and T as T-Mobile. Often MVNOs will fall under the same guidelines as the parent network, but may be less restrictive (US Mobile, for example, will allow devices on their V or A networks that have been blocked on upstream V or A networks).
As a general rule you need to know that for the USA you will need a device that is “4G / LTE capable” as all 3G networks we removed back in 2022/23 and 2G networks were removed by V and A around that same time. T kept their 2G network working for the following few years, but now has shut that down as well. So any phone that does not support LTE (“4G”) or newer 5G simply have no network to connect to. So generally devices before 2018/19 will not function on USA cellular networks, and will be “wifi only” devices. You can check your device at GSM Arena, looking for “LTE” and / or “5G” in the Network section at the top of the specific device specs page.
Second, often phones sold in the USA will be sold in different hardware variants, often “carrier locked” to the network they were sold on: sadly, we love a "pay through the nose with a 3-year contract for a ‘free’ phone here 
. Without getting “carrier unlocked” you will not be able to install a custom ROM. Some are sold “unlocked” and these are the best options. So you can’t just say the “Moto G52” or the “Pixel 6a” will work with all carriers, it depends on which Moto G52 or Pixel 6a.
This said, phone variants for the the A or T networks, while originally carrier locked to those networks, may be able to be unlocked by them, allowing them to work on any of the 3 networks. But the “gotcha” is that often phones carrier locked to the V network are a different hardware variant that will not support the cellular bands used by A or T. This means even if V “unlocks” the device, it will still only effectively work on the V network. V may not carrier unlock the device however, and without being carrier unlocked, you will not be able to install a custom ROM like iodé. Summary: unless you are only on the V or a V MVNO network, do not get a V variant device!! The prices are cheaper, but this is why. Stay away! 
Get the “unlocked variant” and avoid all this hassle.
Next, even after being “carrier unlocked”, your device will need to be “vendor unlocked” to install an alternative ROM. This is immediately available on Pixel devices and I think all OnePlus devices (maybe others), is reasonably straight forward for Moto devices (but you need to use their website, etc) and Sony devices, but you may have a wait period while they verify it. And other devices, like Huawei (no longer in the USA market) aren’t able to be vendor unlocked period so are a no-go (these would not be supported by iodé at all).
Lastly, as of now all Samsung devices with custom ROMs do not support VoLTE, so no voice calls on any Samsung devices!
So how do you navigate all of this when looking at an ebay listing? My advice for USA users is to not use ebay, but instead use a more reputable phone reseller such as swappa.com. Swappa will let you filter by “unlocked” carrier, guaranteeing it will work on any network in the USA. The ones listed as A or T variants are cheaper, but hassle and risk awaits to see if you can get
it carrier unlocked (see above). So just stick to the “unlocked” filter on Swappa. You will pay a bit more, but are assured it will work for you.
If nothing else, Swappa is a simple way to check what the variant serial numbers are for the dreaded “Verizon models”. For the Pixel 6a bluejay, for example, when you filter by “Unlocked” you see the model is GX7AS, but if you filter by V, the model is listed as GB62Z (stay away!). A and T filters show GX7AS but again will need to be carrier unlocked by you (and may not be possible due to their policies).
Good luck! Sorry this got to be so long…
Bootnote: If you are looking for a carrier, personally I use US Mobile for cellular services. They can provide sim cards for the V, T, or A networks, will work with you to get your IMEI approved if your device was carrier blocked by the upstream network, etc. Plus they are relatively quite inexpensive. $8 / month for unlimited voice / text and 2GB data is quite good in the USA (no laughing at us, rest of the world who finds this “way too expensive” … I’ve lived overseas a lot of years and already know).