Can i exclude some of my datasets from the training? Like disabling them to be used
Indeed.
When i disable them they are still included that is why i thought this function is not working yet in edge impulse
What makes you think they are still included?
when i disable some of them they still appears in the data size
Start a new post as a "Feature Requests" to show how the GUI should behave. As labeled "Collected Data" is collected data whether it is disabled or not. Perhaps the GUI should change when the "Collected Data" has a Filter set to one of the combinations of Valid & Invalid Signatures and Enabled and Disabled Samples.