How to limit the number of presentations per session

My goal is to limit the number of presentations per session so that each presenter has enough time for their presentation.

You can assign as many presentations to a session as you like. There is of course a time limit for your conference, but ConfTool does not set a limit.
As a reminder for an upper limit, you can set the maximum number of presentations for each session here:

Please go to:
Overview => Scheduling => Time Periods for Sessions
... and edit all the corresponding time periods.
You can use the option “Max No. of Presentations per Session for This Period” to set the limit.

If you assign too many presentations to a session, the reminder will appear on the session overview page here:
Overview => Scheduling => Edit the Conference Schedule

Sessions with too many presentations will have a reminder highlighted in yellow, displaying the maximum number of presentations set for this time slot.
Please note that the setting will not limit the number of presentations; it solely serves as a reminder.