We would recommend against enabling de-duplication, as this will hurt performance over time. This is why we do not display this as a feature today. We are looking to capitalise on new features, such as metadata offload, to improve performance for de-duplication enabled storage pools. We should have this feature in future versions of QuantaStor.
In terms of compression, gzip-6 provides a good mixture of performance and compression. The higher you go, the more compression you will see, but this comes at a cost of performance.