Best Practice MTU settings for 4G LTE?

Product Discussion Pepwave MAX
1

Hi,
Looking for any feedback on what we should be using as a standard for a MTU setting on 4G LTE modems. We’ve always just left the default of 1428 but have seen the following recommendations to prevent fragmentation.

Verizon = 1420
ATT = 1430
FirstNet = 1342
T-Mobile = ?

We’re usually using Max-BR1 units for very low bandwidth IoT communications and not using FirstNet so assuming I could just use the lower 1420 for both Verizon and ATT? We usually create standard configuration file that gets used on all the units regardless of who the carrier is.

Any thoughts on this and those numbers listed, maybe they have changed?

Thanks