Yes, I've already used it again in 2023 in the USA and Canada and I wasn't in a big city. However the network was not incredible.

Currently the USA are offered by Swiss operators at less prohibitive and the pocket wifi has less reason to be.

The LTE frequencies differ from those specified in the data sheet. It probably works in larger cities.
Why don't you search for LTE frequencies USA, then you can compare them.

The M7350 supports the following frequencies

4G: FDD-LTE Cat4 (800/900/1800/2100/2600MHz)
3G: DC-HSPA+/HSPA/UMTS (900/2100MHz)
2G: EDGE/GPRS/GSM (850/900/1800/1900MHz)