Hi Riccon,
Thanks for showing interest in our Syncfusion product,
As of now, we don’t' have any support to customize the schedule header in Xamarin Forms. We have already planned to provide customization support for header, where this scenario will also be considered with the same and it will be implemented in any of our upcoming release. We appreciate your patience until then.
Please, if you have any further queries.
Regards,
Swathi G