I realize the Obsidian Tasks plug-in does not support an estimated time field and likely never will. It would seem to me that supporting some additional meta-data in the task line such 30min at time of import would be possible. It is easier to determine the estimated time when you create the task then remember when you are scheduling it and you can always adjust it. Seems like a decent workflow benefit. The another option would be to allow setting default time estimates for certain tags such as call=10m, meeting=1 hour. I suppose I could just create a bunch of 15min sequential tags and sort my task list on them but, that seems like a messy workaround.