I have an album dedicated to M42.
In it I have 3, 10, 15, and 30 second subs.
Is there a feature that will display total integration time?
If not, a cool feature would be a read out for selected subs. Shift click two to all subs, right click or press a key combination, and total integration is displayed.
That's a great idea! It currently can't do that, but I'll add it to the list for the next update.
This has been implemented in Observatory 2.0.4.
Just select multiple images or stacks in the browser. The total integration time is then shown in the Overview Inspector, skipping rejected images for this computation. For stacks it uses the sub-exposures.