I found that turning off VSync and setting the FPS limit to 30, along with capping the Steam Deck frame rate at 30 from the UI, gives me good results. I also turned off FSR 1.0, turned on fidelityFX sharpening, and slid the slider all the way to the right. My settings are mostly on low, except for texture quality, which I set to medium.

My FPS isn't always a steady 30, but the game stays very playable, even when it drops to the low 20s. I'm not super picky about performance.

I kinda struggle to get about an hour and a half of gameplay on a full charge (my battery health is at 97%).

I think it might depend on what model you have. I have a hl-l2395dw (monochrome laser printer) and cups has never failed me. I've had zero issues with it and wireless printing works fine, I use arch and mint and both work fine.

Maybe its the newer printers? I bought mine in 2019 or so

My anecdotal experience is based on using cups and not installing brother proprietary drivers

It works offline for me on my steamdeck.

I have a oneplus 8t also. It was very easy to unlock the bootloader and install lineage on it. There's also the MSM tool that unbricks the phone as well. There's also a way to update the firmware without installing OOS, which is nice.