Does Cbor support schema evolution?

[kant111]

Can a writer and reader have different schema ?

[ii8]

yes.

If the writer has this CDDL schema:

something = {
  member: bool,
  member2: uint
}

and the reader has one like this

something = {
  member: bool
}

then the reading implementation can access member without issue.
There may be caveats depending on the implementation, for example if your decoder checks that the incoming data contains nothing extra to what is defined in the scheme then naturally this wont work.
And other common sense stuff like indices in arrays can't change etc.