I don't understand why you would bother with this when you can pick up a second-hand Thinkpad for so cheap which brings a builtin UPS and far more performance, RAM, and IO options.
Just for context, you can fit about 10 raspberry pi 4s in the same volume you fit your used laptop, and for the price of an old end-of-life Thinkpad you can buy 5 or 6 RPis. Hell, you can go to any online store and buy dozens of RPis in a couple of clocks and have them delivered to your doorstep in a few days.
Meanwhile, your cheap Thinkpad is already in the tail end of its bathtub curve.
I'm going to go out on a limb and assume the average HNer already has numerous retired laptops collecting dust in a corner, all more powerful and better suited to connecting high-speed storage to than any Raspberry Pi. They're already wasting space and have already been manufactured, instead of adding more e-waste piecing together Pi-based storage contraptions just turn one on and set it up for server duty already.
..when describing hardware used for mostly trivial purposes. The mentality of just clicking up some new hardware with no consideration of e-waste has to stop.
Anecdote; my last laptop was a used T420. $80. You're lucky to get two Pi+SD card+power supply for that.
That said, x220s and x230s seem to have gotten more expensive since then, I haven't seen any similarly good deals lately.
I could have used a thinkpad with a usb DAC, but it would require more space, more power cable, ... It would provide a built in ups and screen, which I don’t need.
I think rpi are OK when the whole service it provides could be read only, with no local storage / state.
Most things I use Pi's (Raspberry and other flavors) for are headless.
Sure I could probably fool around with a logic analyzer and try to figure out some way of fooling the motherboard it has a monitor, but meh, Pi's are cheap and easy and just work.