Businesses are now slowly coming to terms with the new institutional arrangements for Northern Ireland coping with the protocol agreed between the UK and the European Union.
Already it is clear that in the coming months some of the rough edges of the new rulebook will need to be smoothed.
An early and unnecessary problem is the suggestion that, after a temporary exclusion, all goods sent or posted into Northern Ireland from Great Britain should require customs declarations and could be liable for duty, as if being imported into the EU.
When the protocol was initially defined the expectation was that trade within the UK should be unfettered.
Then this was expressed more carefully so that the arrangements would identify goods 'at risk' of being consigned through NI to reach the EUropean Union, and using this routing to avoid EU duties. In order to identify goods 'at risk' of being routed through the back-door, duties should be collected, and that (for now) includes smaller personal consignments which carry little risk of distorting trade.
A grace period applies until April 1 but we don't know what rules wil apply aftewards.
The unintended imposition of customs duties after the exemption now needs to be corrected.
Economy Minister Diane Dodds has asked Cabinet Office Minister Michael Gove to investigate.
Procedurally, this unintended consequence should be dealt with by the Joint Committee that has been set up under the final agreement between the EU and UK.
This example of a trading complication is a first test of the work of the Joint Committee.
If Mrs Dodds hopes to get an acceptable answer, then this should come from a meeting of that committee which will have representatives from Northern Ireland and the Republic taking part.
As a possible solution, it might agree that small consignments, up to an agreed valuation limit, would be excused duty payments because they are usually not part of business to business transactions.
A simple free sticker on postal packages or online shopping declaring the contents as being not commercial or being valued at less than £150 would help most of the innocent transactions.
In a parallel illustration, a form of trusted trader recognition scheme might be used to allow shipments on a commercial scale that are genuine GB to NI transactions.
The example of unintended difficulty caused by the protocol emphasises the need for a transparent mechanism to allow workable commercial relations on this island.
Joint Committee meetings and their agendas should be published.
The new trading and commercial environment affecting businesses in Ireland, north and south, must now be used as an opportunity created by the unique status of Northern Ireland.
The search is now on for relationships that allow NI to gain advantage from the best of both worlds from within the UK and also from within the EU market for goods.
The mechanisms of the protocol are now in place. They cannot be ignored even if, controversially, some groups are hostile.
There is now a new opportunity to maximise the benefits from a reshaped shared experience across the island.
The ambition of Taoiseach Micheal Martin, when he set up a think tank model to explore the potential benefits of shared experiences across the island of Ireland, should be accepted as a potential source of mutual benefit, north and south.
The political and institutional arrangements across the island of Ireland reflect two separate systems.
Indeed, they might be described as a series of structures reflecting differing degrees of political and cultural separation.
The current systems have created a complex network of decision-making authority where, for example, Northern Ireland has devolved responsibility for many aspects of Government economic policy but is constrained by overriding aspects of policy from the UK Government. The Irish Government, seeking to develop policies for the shared island, must recognise the asymmetry stemming from the political inheritance.
Nevertheless, there is a range of competences shared, for Northern Ireland and the Republic of Ireland, that create scope to demonstrate the possible gains from a vision of shared island economies, as a partial reflection of issues which might draw on decision-making by the national Governments.
Making the protocol work is an unfinished agenda for mutually agreed refinement.