1/ The Health Protection (Coronavirus) (Restrictions and Requirements) (Local Levels) (Scotland) Amendment (No. 3) Regulations 2020 are coming into force at 6pm Friday and need consideration in light of the UK's constitutional arrangements:

https://www.gov.scot/publications/health-protection-coronavirus-restrictions-and-requirements-local-levels-scotland-regulations-2020-amendment-regulations/

2/ In Holyrood debate yesterday, they were defended by the SNP minister Aileen Campbell as comparable to the restrictions put in place in Wales.

3/ But it is worth noting that the debates, and the guidance notes on the measures, do not address the competence issue under Schedule 5 of the Scotland Act, which reserves movement of persons to Westminster (see the concerns of @ProfTomkins)

4/ There is also a lot of making things up on the hoof. The CTA doesn't divide up the UK into constituent parts. You'll look a long time for mention of England or Scotland in its core documents:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/800280/CTA-MoU-UK.pdf

5/ These regulations do atomise the CTA in this regard, treating Northern Ireland as a CTA "country" (more grist to the debate on what to call NI):

6/ V importantly, when food security and Northern Ireland is such a feature of the Brexit debate at the moment, the exceptions in the regulations do allow for work (so these regulations aren't a threat to movement of goods through Cairnryan)