Need some suggestions for a DAC for RPI zero 2w

[Nutul]

Curious to know why you suggest USB DACs, are those more likely to receive driver/firmware updates?

They don't need any driver under Linux environments, moOde being such...

I'm not sure where to start but of course Linux uses drivers, they are just mostly built into the kernel. More exotic hardware needs drivers which are not included, so you would rely on open source or on the manufacturer of the hardware device to supply them. 

I wouldn't mind a USB DAC, provided it uses very common hardware and the manufacturer does provide stable drivers or even better if its driver is included in the Linux kernel.

As I said, in Linux (that is, in moOde) you don't need drivers to use the audio protocol, be it USB-1 or USB-2 (note, this has nothing to do with USB 1 or 2 or 3, etc. it's an asynchronous audio transfer protocol, actually, the newest one, with - hardware implementation dependent - plenty of room for DSD512 / PCM 768).

All DACs that connect to the PI over the feature connector MAY or MAY not require specific drivers (and most of them do...), but USB is a complete different story.
You may need USB drivers (in Linux I mean) if you want, for example, to change one of the (possibly available) FILTERS, that is: use specific device parameters; but these do not include/affect the USB-audio protocol itself.

For something concrete, I was thinking about the Topping E30 (Everybody talks wonders about this DAC) but its price is about 150 USD. Valid alternatives may be Topping DX1 at 100 USD, Fosi Audio K5 Pro at 80 USD, SMSL Sanskrit Mk II at 140 USD.

All the above offer USB, COAX and OPTICAL inputs and RCA preamp outs. All are USB powered.

Hope this helps, enjoy.