Is there any image for allwinner A23 ?

Quote from Uphantom88

I do see that we have rom for a10 & a20 devices

Not really, support was dropped, so only unmaintained images exist.

In short, no.

Long answer: A23, as you said, is very similar to A20, so it has same issues. No HDMI audio (patches exist, but have some issues), no HEVC support (if you need it at all), limited memory bandwidth, HW deinterlacing would be hard to implement. I also don't have any board with A23.

If someone steps up as maintainer and kernel developer (for missing features and fixing bugs), we can (re)introduce support. However, it's hard to find such people.