Hi Sean,
Great questions!
Short answer to #1 - The recommended way to get these insights is by implementing a smart deliverability monitoring tool.
These tools offers a comprehensive deliverability and threat monitoring that provides actionable insights that will help you reach the inbox.
You can easily get insights related to inbox placements, tab placement or if there are any blacklisting issues.
Regarding point #2, it involves a strategic plan of action and guidance on how you can improve the deliverability and user engagement. Landing into promotion vs primary tabs is all about Gmail ML algorithms that’s driven majorly by recipient’s behaviour.
Like to know more, happy to hop on a call and talk about it.
Regards,
Mohsin