The profile reporting tool has only this about the ECDSA signature format:

Profile SecurityPolicy [ECC-B] – ECC-nistP256
CertificateKeyAlgorithm_ECC-nistP256
https://profiles.opcfoundation.org/conformanceunit/2471

"The P-256 or P-384 curve described in http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf.
ECC public key compression is not used.
ECC coordinates are encoded as big-endian integers padded with zeros.
Signatures and keys are 64 bytes or 96 bytes."

This does IMHO mean that the ECDSA signature
is encoded as r, s values in big-endian zero padded binary format.
while the public key is encoded as x, y values also in big-endien zero padded format.

We should make that more explicit in the profile reporting.