If you like the look of carnauba, I would just use that for a few reasons:
1. The oils in a carnauba can permeate some polymer sealants decreasing durability. Kind of defeats the purpose of the sealant underlayer
2. The oils in a carnauba attract dust, again defeats the purpose of a sealant, which tend to have more of an anti static, non-stick surface characteristic.
3. The hi-solvents in a carnauba based system can strip or etch the sealant underlayer, again, defeats the purpose of using the sealant
4. Once you use a carnauba/oil based product over a sealant, you limit your ability to layer the sealant until the carnuba / oil layer is stripped.
As a compromise, if you want the durability of the sealant with more of a carnauba look, I would use an oil based QD instead. It is "less harsh" than a solvent based carnauba wax and won't hurt the sealant layer as much. It will also wash off easier for when it's time to put another sealant layer on.
Last, based on my experience and opinion, I feel that the best topper to a layerable sealant, is another coat of the same product. Typically, each coat gives additional return on gloss and protection.