I frequently use the Extbase DebugUtility (Tx_Extbase_Utility_Debugger::var_dump($object)).
It displays additional data for each property, especially the "modified" flag - see screenshot.
How can I access this "meta property" from within my controller (updateAction)?
I tried $object->getProperty->isModified and other combinations, to no avail.

There is a method $yourObject->_isDirty("propertyName") which returns true if it has been modified (see documentation).
If your property is a collection itself, then just use $yourObject->getWhatevers()->_isDirty() (see documentation).
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