Cellular communication on the American iPad in Ukraine/Russia: will it work?

Question

iPad

I want to buy iPad 5/6th gen or Pro 9.7 2016 on Amazon/Ebay with cellular.
Offered for US carriers: AT&T, Sprint, Verizon, T-Mobile. Will they work with Ukrainian/Russian sim cards? Googled, most write that everything works, although there used to be a strict division into a CDMA model (without a physical slot for a SIM card) and GSM: for example, on the iPad 3, where the A1403 model is CDMA, and the A1430 is GSM.
Delving further, I read that they began to install multi-standard CDMA / GSM / LTE modems. That is, you can buy any tablet with the above operators, it will work.
But why then write the names of the operator near the name of the tablet, if the radio modules do not lock and they support all available ones?
And it seems like none of them locks the GSM modem.
And as I understand it, marked bad imei / bad esn will also work?
True judgments or not?
Thinking based on:

List of sources

https://appstudio.org/ipad
Будет ли американский Ipad Air работать в наших сотовых сетях?
https://4pda.ru/forum/index.php?showtopic=169582&s...

Answer 1

In order to understand whether a mobile device released for a foreign market will work for you, you need to consider several points:
1. In the documentation for the device (or on the box), find the list of Bands (frequencies) for which the device was released. Compare with your carrier's Band list. The list may not overlap. This entails the inoperability of the device, for example, in 3G or other networks (depending on the missing Band);
2. Binding the device to the operator (network blocking). It is often practiced abroad to sell devices at a significant discount, but with a service contract with only one operator. To prevent the user from changing his mind, a network lock is made. Those. in this case, the Russian SIM will not work in such a device.
The first problem is almost impossible to solve.
The second problem can be solved by specialized specialists.