As a developer, I have no way of determining how much revenue my game is making unless it only has 1 Place.
The only way to do this is to export a csv spreadsheet of all sales (month to date), export this to Google Sheets, and tally up all sales. I then plug this data into our own graphs. This must be repeated each day to build a Daily revenue graph.
This is because our game has 20 sub-places, and Developer Stats only show revenue for each place individually.
The same applies to visit length - we have no idea what our visit length looks like in a multi-place game until we write our own analytics solution to track this. I believe Roblox has this information internally but does not share it with developers.