BitLocker, ReFS, and Storage Spaces

Hi everyone,

I'm configuring an installation of Windows Server 2016 Essentials. Ideally, I'd like to put into production a Storage Space based on ReFS which is encrypted with BitLocker. Before continuing down this route, I have a few questions:

1. Has the issue of volume corruption when using the combination of BitLocker and Storage Spaces been resolved?
2. When creating a mirrored (2 x 3TB) Storage Space based on ReFS, a new and empty volume (i.e. no previous or current data written) uses approximately 43GB of space. Why is this?
3. When creating a new Storage Space, is the default value the maximum value (without over-provisioning or under-allocating)?

Any clarification will be greatly appreciated. Thanks!