I only use Synapse Dedicated SQL Pool (fka Azure SQL DW) as a tap, not a target.
There are some issues with SQL DW (or PDW as it is called for when it used to be on-prem ... not that many people would have been able to afford it ...) when using the existing tap though.
https://github.com/wintersrd/pipelinewise-tap-mssql/issues/28