Are you aware of the SAP Notes that mention configuration and technical changes with respect to Brexit?
I could find at least 60 valid notes, depending up on the political decision and Brexit outcome.
Almost all of these SAP notes discuss configuration changes that could be relevant to you, if your business operates in the UK and/or in the European Union.
While Note 2768412 provides a number of recommendations in FI, 2766992 describes changes that could be required within Global Trade Services (GTS).
Notes 2753338 and 2754659 even talks about the recommendations for a possible no-deal outcome.
Here’s the current (updated on 6th March 2020) list of available notes: