Quick answer: Valve's October 15 Proton Experimental update makes Breadbox playable and fixes crashes in ARC Raiders and C&C Red Alert.
ARC Raiders players on Linux and Steam Deck have one less crash to worry about. Valve's October 15 Proton Experimental update fixes a rare crash in the game, according to the Proton changelog on GitHub. The same update makes Breadbox playable, fixes a crash regression in C&C Red Alert, Counterstrike and The Aftermath, and fixes a controller hotplugging regression in Chrono Trigger.
The full changelog lists plenty more that has landed in Experimental since Proton 11.0-2, including a fix for a Proton Experimental regression that made CEG-protected games unplayable, a fix for Crysis and Crysis Wars not being playable with some newer AMD CPUs, and a fix for a crash in Terminator: Dark Fate - Defiance.
GamingOnLinux describes Proton Experimental as the testing ground for future numbered Proton releases. The latest stable version is Proton 11.0-2, and a Proton 11.0-3 release candidate is in testing. If you already have Proton Experimental installed, Steam Deck HQ says the update should download automatically. If you don't, you can search for Proton Experimental in Steam and install it.