It is not necessary. You can disconnect your calendar and invite firstname.lastname@example.org as an attendee to each one of your meetings (here). You can also use an immediate invite form instead. Syncing calendars removes many issues related to inviting Sembly manually, like:
-inviting Sembly from the email that is not registered or aliased in Sembly and forgetting to add aliases;
-the constant need to remember to add email@example.com to the meeting attendees;
-need to remember to open Sembly webapp and insert meeting details.