Is It possible to modify the default time of the reminder for Engage invitations In CRM?
Currently, It is not possible.
The Alert for Calendar reminders sent using Approved Email is hardcoded to 10 minutes and cannot be modified. Note that each email client applies this alert differently.
Google Calendar applies the default alerts that the recipient configures over the alert in the ICS. Outlook overrides the alerts set up by the recipient with the Alert in the ICS.
Vault Help Documentation: N/A