In case anyone is not aware, https://github.com/rclone/rclone written in Go is the established swiss army knife of cloud storage sync, and supports mounting on Windows with many caveats (https://rclone.org/commands/rclone_mount/).
Congratulations on hitting the HN frontpage with your new project, mounting cloud storage locally is definitely a topic of interest!
Thank you for your comments. I found WinFsp to be very practical, so I tried implementing it in combination with the AWS SDK. While I believe RClone should be used in practice, I want to continue development for experimental purposes as well.