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As if it wasn't bad enough that they want me to use a random internet service to add a keyboard to a usb wifi receiver, they have the balls to put this for Firefox users. I clicked out of pure curiosity, as I'm not even remotely interested in involving a corporate internet service in getting my keyboard connected to my computer. This is the message you get now on Logi Options software if you have a Unifying Receiver: 
For the curious: https://logiwebconnect.com
EDIT: some people on the thread have brought up that the error message being displayed for Firefox users is due to the WebUSB API not being implemented by Firefox due to security concerns. This still does not justify having to use a web app to plug peripherals to a PC.
Ran into double clicking issues on my two G903s, eventually ended up putting some aftermarket switches on the second one. They would be the YIMAGUJRX RUNJRX Red Kaith GM 4.0 Mouse Micro Switches on Amazon. That was 2 years ago, longer than either of the two G903s lasted (and I did swap my first G903 switches with some Japanese omrons from Muccus brand, but they ran into the same issue after a while), so you might want to look into whether the G604 can use them. It's ridiculous that the end user would need to end up learning how to solder and get soldering gear to fix a high end product after a year...twice....but here we are.
As for the Onboard Memory Manager, I'll have to look into that one. I hate having to have GHub running lest I want a rainbow mess and no macros on my G903.