The only issue with that might be the same problem I am having with ÖGK. ÖGK requests information from the HMRC via EESSI (electronically), HMRC denies receiving it. Until ÖGK receives the information, they won’t do anything. I have logged this on SOLVIT and the British Embassy in Austria
In my case I have requested form CA3916 from HMRC myself (in the post apparently) and a letter from NHS Business Services Authority saying I am no longer “insured” with the NHS in the UK (received today).
Fingers crossed ÖGK will move their position tomorrow as I have already provided them with other background material (e.g. letter from my GP and NI summary)