Police Clearance Certificate - NI and Scotland/UK

My partner and I are applying for de facto and one of the requirements is a police clearance certificate.

He lived in both NI and Scotland within the past 5 years. We can't seem to ascertain whether he should apply for an ACRO certificate or will need AccessNI for NI and a Disclosure cert for Scotland. ACRO usually does police clearance certs for US, NZ, Canada etc. but I am not certain they would include Ireland or if ACRO would have access to Scotland/NI police records? Does anyone have experience with these?

https://www.mygov.scot/police-record points you break towards ACRO for a certificate for visa purposes. PSNI also point you in that direction if you need a PCC. So it looks like the ACRO PCC would cover the whole UK. Whilst the sites explicitly list countries they know accept PCCs... It sounds like the Irish state have asked your for PCC and it looks like the only body in the UK that issues one is ACRO, so I'd go for that