For the embedded LTE modem on cellular Meraki devices, here is the synthesis of my searches :
MG21 : Gemalto Wireless Module Cinterion : PLAS9-W (LTE (1, 3, 5, 7, 8, 18, 20, 28))
MG41 : Telit Cinterion : LM960A18 : LTE Cat 18
MG51 : Telit Cinterion : FN980 : LTE Cat 20
MG52 : Telit Cinterion : FN990A40 : SA (and NSA) 5G sub-6 FDD and TDD
Z3C : Gemalto Wireless Module Cinterion PLS8-E (LTE (1, 3, 7, 8, 20))
Z4C : ??? (unfortunately cannot find the exact model)
MX68CW : Gemalto Wireless Module Cinterion PLAS9-W (LTE (1, 3, 5, 7, 8, 18, 20, 28))
MX67C : Gemalto Wireless Module Cinterion PLAS9-W (LTE (1, 3, 5, 7, 8, 18, 20, 28))
If someone has the Z4C CAT 12 LTE modem information, it will be highly appreciated 🙂