To put it simply, the Framwork laptop has stole my interest. I have a few ideas for Expansion Cards
*LTE card, so you can bring it with you and not have to worry about wifi.
*Battery extension card, I dont know if this would be as effective given their size, but it would be cool. Because it could be used either to power the laptop itself longer, or used as a battery pack for your phone that has a nice and small form factor.
*Custom button card, this could be a physical button coming out of the side sticking out, which can be programmed to do whatever you please.
*Volume control card, this would be a card with a small touch pad on the side sticking out, which you slide your finger across to control volume, or anything that can be throttled up and down.
*Screen recorder card? I dont really know the physical demands of a capture device, but from my experience using software to record my screen reduces performance by quite a bit. The recorder card would have just a red button on it, pressing it will make it glow red as in you are recording your screen. Pressing it again will stop recording and save to the drive.