The correct steps for upgrading a HA cluster using MVC are as follows:
Upgrade the passive node M2 to R81.20 using CPUSE or CLI.
Enable the MVC mechanism on the upgraded R81.20 Cluster Member M2 using the command cphaconf mvc on.
In SmartConsole, change the version of the cluster object to R81.20.
Install the Access Control Policy and make sure that the installation will not stop if installation on one cluster member fails.
After examining the cluster states, upgrade node M1 to R81.20 using CPUSE or CLI.
On each Cluster Member, disable the MVC mechanism using the command cphaconf mvc off and install the Access Control Policy.

Log Consolidator is NOT a SmartEvent component. SmartEvent is a unified security event management solution that provides visibility, analysis, and reporting of security events across multiple Check Point products. SmartEvent consists of three main components: SmartEvent Server, Correlation Unit, and Log Server. SmartEvent Server is responsible for storing and displaying security events in SmartConsole and SmartEventWeb. Correlation Unit is responsible for collecting and correlating logs from various sources and generating security events based on predefined or custom scenarios. Log Server is responsible for receiving and indexing logs from Security Gateways and other Check Point modules. Log Consolidator is not a valid component or blade of SmartEvent.

The cloud-based SandBlast Mobile application that is used to register new devices and users is Check Point Gateway. Check Point Gateway is a web portal that allows administrators to enroll devices and users into the SandBlast Mobile service, which is a cloud-based solution that protects mobile devices from advanced threats.
Check Point Gateway also allows administrators to configure policies, monitor device status, and generate reports for SandBlast Mobile.