Made a minor error with all the messing around with aknlayout.lag which meant it got performed on the default branch.
#include <platform_paths.hrh>
PRJ_EXPORTS
simutils.h ssm\simutils.h
startupdomainpskeys.h ssm\startupdomainpskeys.h
startupreason.h ssm\startupreason.h
ssmdomaindefs.h ssm\ssmdomaindefs.h
ssmstate.h ssm\ssmstate.h
ssmstateawaresession.h ssm\ssmstateawaresession.h
ssmstates.hrh ssm\ssmstates.hrh