Hi, thank you for doing the right thing and asking first!

You have three excellent answers, but I'd side with the learned Grandfather over the learned davido on whether or not to create a new top-level namespace. In this case it's certainly not needed as you have the Device:: top-level space, where there are already sub-names representing commercial brands, eg Nest ...

So my humble recommendation, since the software is exclusive to LG, would be that you create a top level package at Device::LG::QuickMemoPlus and put your functions in a subclass Device::LG::QuickMemoPlus::Extract. I find this straightforward and descriptive and that it leaves room for you or other authors to add other packages under the namespace in future.

Hope this helps!