AFAIK there's no particular requirement for fire containment for DBs in schools - for domestics (only) BS 7671 demands CUs are either manufactured from non-combustible material (steel) or enclosed in the same - but makes no particular demands on fire stopping holes even then. Of course designers are free to specify to a higher standard than BS 7671's requirement if they think fit for the particular circumstance, customers may well have their own particular demands too (perhaps as part of a wider fire risk assessment for example), but otherwise I think it's just a matter of the general principles of good workmanship and following manufacturer's instructions.

   - Andy.

You could have a look at envirograf.com their EnviroBurst seems to look useful without being too expensive. 

It would be useful to fit a battery powered backup light above CU/DB for when they need to flick the breaker back on

Advocate the installation of a smoke/heat alarm that is interlinked above CU/DB in the fire rated cupboard

intumescent strip and FireMate can and should be used when there is compartment or building fabric penetrations.