Aa a QField project creator, it would provide a huge increase in functionality to be able to perform actions based on when a specific field is updated at time of initial collection (before the feature is saved) and/or on updating an already saved feature.

For example: perform/update a calculation when another field is changed. I understand virtual fields and default values, etc exist, however, QField does not seem to trigger field updates the same way QGIS does.

Having access to events at form level: on_form_open, before_form_close, etc and at field/attribute level: on_value_change, etc would provide much more granular control over data collection without the need of going to a full custom form UI via python Qt Designer.