You are not alone, we have the same limitations and challenges. It's been this way for a long time. I'm hopeful this will change in the future.
Please refer to the deployment guide, page 20, to see all the limitations:
https://www.cisco.com/c/dam/en/us/td/docs/telepresence/infrastructure/tmsxe/install_guide/Cisco-TMSXE-Deployment-Guide-5-8.pdf
Booking Limitations
If booking a meeting through Outlook, Cisco TMS, or any other booking interface, whose duration is three minutes or less, the meeting will not be processed by Cisco TMSXE.
■ Cascading to additional MCUs when the number of participants exceeds the capacity of the first MCU is not supported. To support such scenarios, set up Cisco TelePresence Conductor as the preferred MCU in Cisco TMS.
■ When a service user is performing all bookings, the booking permissions are the same for all users. Individual permissions and restrictions in Cisco TMS are ignored.
■ Meetings in the past cannot be changed or deleted, and you cannot move a meeting from the past to the future.
■ If sufficient system licenses are not available at the time of editing an existing booking, the booking will be deleted.
■ Yearly recurrence is not supported.
■ When the Smart Scheduler is used, booking permissions for endpoints configured on Cisco TMS through Microsoft Outlook using Cisco TMS/ Cisco TMSXE combination, works in the expected manner. However, permissions configured on Cisco TMS for video endpoints are not adhered, when booking is done using the Smart Scheduler.
Booking Horizon and Recurrence
Cisco TMS will decline any meeting request that is not within its booking horizon or that has an unsupported recurrence pattern:
■ Series with more than 100 occurrences or with no end date.
■ Meetings including occurrences outside of the Cisco TMS booking window. We strongly recommend configuring identical booking windows for Cisco TMS and all integrated resource mailboxes in Exchange.
■ Meetings in the past.
■ The declined meeting will also be deleted from Exchange's resource calendar.
Ongoing Meetings
Updating a single meeting that is currently ongoing is possible, but will not always be successful.
■ Modifying any meeting, extending the meeting will fail if it creates a booking conflict for any of the participants.
■ Modifying single meetings, including meetings that are part of a series:
— Editing the start time will not work and Cisco TMS will throw an exception.
— Editing the meeting so that it would be required to be disconnected and re-routed will not be successful. For example, if the meeting is using a bridge that does not support WebEx, you cannot add WebEx during the meeting.
— Any other aspects of the meeting can be modified, but if the number of participants exceeds the available capacity of the MCU or TelePresence Server, Cisco TMS will throw an exception and the participants will not be added.
■ Deleting a recurrent series while a meeting in the series is ongoing will cause the ongoing meeting to end.
■ Modifying a recurrent series while a meeting in the series is ongoing will turn the ongoing occurrence into a single meeting, separate from the series:
— Any occurrences of the modified series that are in conflict with the ongoing meeting, will not be created. — Any past occurrences in the series will not be modified.
— Pending occurrences are assigned new conference IDs.
— If the end time or date is edited for the series, the entire series will get deleted.
— Any changes done to the series that creates conflict with the separated meeting will delete the series.
■ Editing an ongoing meeting's end time to overlap with a future meeting may lead to deletion of the ongoing meeting
