Whenever a device is plugged in, it’s gets warmer. When it’s both charging and turned on, it can get hot, which could lead to disastrous results. In addition, from what I understand, batteries can wear out from repeated charge cycles. While the Steam Deck stops just short at 99%, I’m worried that leaving it plugged in could rapidly make it go through several cycles.
Is this something that I should be concerned when using the dock?
The Deck has a pretty effective way of processing heat. The official Dock, which was designed to function with it, is also effective at keeping the heat in check. The Deck also has a method of discharging the battery when it’s been left plugged in a long time, which prevents wear and tear.
One day your battery will get worn out from repeated charge cycles. By the time that happens, though, it will be time for a new model anyway. Comparatively, it takes about three years for your phone battery percentage to start diminishing. That’s from carrying it around everywhere you go and charging it consistently every day. It’s likely you aren’t putting your Steam Deck through that much use (unless you are able to freeze frame time.)