Any such commemoration of the Act of Union will be controversial, public institutions tend avoid such controversy as it could cause ill favour. Whilst many Scots have not negative opins of QE and QETQM, any other association with England might indeed be found not in such high esteem with the average Scot.
There really are way too many commemorative issues emanating from each of the three institutions, few of any of which in my opinion are suitable for commems, other than to proffer off quite profit making ventures off on a gullible public.
In my reckoning the following have been worthwhile:
300th anniversary of Bank of Scotland
50th Anniversary of Queen Elizabeth's reign
100th birthday of Queen Elizabeth the Queen Mother.
200th Anniversary of Robert Burn's death:

And some of the lesser importance, as in should we commemorate the Prince Charles wedding with horsey face, whoops I mean Camilla:
Jack Nicklaus, purely aimed at profiteering from golf afficianados
Commonwealth Heads of Government mtg in Edin.
Glasgow UK City of Architecture and Design:

Some of the commems have been stunningly beautiful, as in the case of the Glasgow University commems, but at £150 for a set, forget about it.
I think it was the commems that finally convinced me to go back to purely collecting Scottish coins and giving up on the banknotes at least the new ones, but auld ones I love:

Or older and rarer:

Or even older and bolder: