Possible to read and write Valeo VD56 PSA with Xhorse multi prog?

Yes. it does.

For example:

It is a Peugeot 208, V56 ECU.
Flex doesn’t have Boot protocols. Foxflash won’t do boot for this one.
But Xhorse multi prog will read and write.

VD56 GPF OFF, DTC OFF, read and write by multi prog.

But will not carry out checksum correction.
Checksum manually With winOLS or Lsuite.