No, this is not done with SMBs, this is some misunderstanding only ! MAC is a prominent part of the device and found on the shipping cardbord box:

On the bottom of the SMB device:

The only situation i have to use an IP address for licensing is for longer POCs/Demos or LAB demos and All-In-One EVALs. You can read all about that here: https://community.checkpoint.com/t5/SMB-Gateways-Spark/1400-1100-1200R-700-600-Appliance-Demo-Units/... - but be aware that starting with R80.20.xx firmware, only SMBs without WLAN can use them (as they do not contain the special license and country code needed for it to work), if WLAN is buildt-In, licensing is impossible.
CCSP - CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist