LiteSpeed supports TDE enabled backups, however there are some issues (on Microsoft side) with using compression on these backups with VDI.
These issues have been fixed with SQL Server 2016 SP2, and backup compression for TDE databases are supported in LiteSpeed version 8.7.
More information from Microsoft is available through this
link.
Microsoft will support TDE compression in Sql Server 2017 with SP1 (VDI fix for TDE). When that SP is available, then LiteSpeed will support it shortly after.
