In R2021x FD02 (so current CLOUD!) there is a new way to load the robot.

After ‘Install optional content’ you will see the …/B423_Cloud_Content\win_b64\startup\Robotlib  directory for each Robot provider (instead of huge 3DXML!) and under each directory one 3DXML for each Robot !

So now you can easily load only your robot and not his “family”