Do I have to go through BT qualification if I use the BL654 dongle in my product?
It depends on how the BL654 dongle is being used.
As a consumer you are not required to go through the qualification program. You can buy any commercially available dongle, headset etc. For example, a Linux PC would have a Qualified and Declared Host Subsystem and the Dongle would be Qualified and Declared as a Controller Subsystem. Each part would have been Qualified and declared by the manufacturer who has agreed to the two licensing agreements.
If you include the BL654 in your own product, for example plugged into an internal USB port, then Yes, if you are selling the Dongle as part of a product and it supports Bluetooth functionality then you are required to go through the qualification program. In this case it should be Qualified, via the simple Declaration model.
The above also applies if you are plugging the BL654 into an external USB port as part of your product. The interface is irrelevant, it’s the use of the Bluetooth IP in your product that would trigger the need for Qualification.
If the BL654 is an optional part of your product then the Bluetooth option should be Qualified, via the simple Declaration model.
If you are including some Bluetooth IP no matter what the interface used, and representing the product as your own then they would need to go through the Qualification and Declaration process, only a retailer who simply sells an already qualified and declared Bluetooth Product, manufactured by a 3rd party is exempt. If the retailer represented the product as their own, like Amazon branding a dongle, then they would have to go through the qualification process.