If you revoke ‘ure_manage_options’ capability for user, he will lose access to Settings->User Role Editor page and stop be superadmin for URE.

Workaround scenario:
If you do not use plugins which directly require ‘administrator’ role instead of some user capability, you may create a copy of ‘administrator’ role for additional administrators and block this role (and users with this role) from themselves via “Other roles access” add-on.
Then do not use user with ID=1 in a daily work.