Behringer just announced they will be releasing an all in one DJ deck with no software but the freedom to install whatever you want on it, for a tiny fraction of the price of the existing options. There's https://thefirmwarehub.com/ with a whole load of custom firmwares for a $60~ synth. And the whole industry of retro emulator handheld consoles coming out of China where the first thing you do after unboxing is replacing the stock OS with a custom one from github.