I'm using Commerce 2.0.2 with the hotfix for COMMERCE-1786 applied.
I'm able to receive the Order Placed notification email when placing an order. However, when changing the Notification Queue Entry Check Interval setting under Control Panel > System Settings > Orders > Commerce Notification Queue to 1, the email is still sent the default 15 minutes after the order is placed instead of 1 minute.
Notification Queue Entry Check Interval setting:
Order Placed notification configuration:
Debugging Commerce 2.0.5 source: