I have no idea if L4 and R4 have any use by default, but you can probably map them to the actions you'd like in games that allow remapping controls even when using a controller. Of course usually when a game supports controllers, extra buttons aren't needed, but they could still prove useful in some games. For anything of console origins, especially older consoles, I wouldn't expect there to be great options for mapping buttons t hough.

I've been using an 8BitDo Ultimate for Switch 2 and laptop. I like the design but durability has not held up compared to other controllers like my DualSense or Xbox controllers. No drift but the sticks are noticeably more wobbly than when I first bought it and the left one actually cracked on me after 9 months. Thankfully that's still under manufacturer warranty and 8BitDo is sending me replacement parts. We'll see how that ends up going. In the meantime I've gone back to Xbox for PC and the 8BitDo will be just for docked Switch 2 play assuming I fix it successfully.

OpenAI is shutting down its generative video app Sora. Presumably it was highly unprofitable and they need to drop ballast for their IPO. SeeDance is also having uptime issues too, though. Perhaps generative video is starting to get a reality check; it's certainly way more computationally expensive than most other types of content.