It's potentially a sudden brittle failure when it goes (i.e. zero warning of a change from 'looks OK' to 'pile of rubble') and I find it a little hard to categorise any realistic risk of 'pile of rubble' as being something that you can be excessively causious about.  A structural engineer doesn't like brittle failure.

However, I note that the IStructE guidance is itself risk-based - "Assessments of buildings with RAAC panels are recommended to include a balance of risks for the continued use of the building against the benefit of strengthening or replacement of the panels. The assessment should include a robust risk assessment and include consideration to the on-going monitoring and future management of the RAAC panels".  It has a range of remediation alternatives from full replacement to relatively minor end bearing enhancement (it's an end bearing failure that's teh most likely brittle) and various differing additional support options.

We are not doing anything other than IStructE guidance.  However, we are doing very little in this area - our insurer is happy for us to do desk studies and site visits and advise clients if they do have RAAC, but we are very cautious about advising they don't have RAAC, and we are not getting involved in any remedials other than full replacement.