Is paid work by the client but offered free to end users considered to be a "commercial product"?

My team and I are interested in using UE4 for a client that we have. They are paying for the development of an application that we’re using UE4 to build, and the application will be available for free to their customers (ie. the app is packaged with the hardware they’re selling and the app is free to download on their website).

Will our application be deemed as a ‘commercial product’ and will require us to pay royalties?

I have read both the Game-Engine-Technologie von Unreal - Unreal Engine and the Häufig gestellte Fragen - Unreal Engine but our situation relies on the definition of a ‘commercial product’ which lead us to https://www.acquisition.gov/far/current/html/Subpart%202_1.html. But it is still difficult to interpret for our situation.

So the contracting work appears to be custom work-for-hire fees which are royalty free.

As for the end user distribution, if it’s free of charge, there’s no royalty. But if it’s bundled with hardware that’s sold, that could be a way to hide revenue for the software (i.e., the software is “free” to avoid royalties but is a large part of the value of the hardware with which it’s bundled). We may need more information to make a call there.

The application that comes with the hardware is more of a short trailer advertising their line of products. It is not the main reason for purchasing the hardware.

Are we in the clear here?

That sounds alright to be royalty-free.

Thank you.