Hi @aran_anderson,
The RTD package includes the Peripheral Access Layer for S32K3 headers under the Base component (C:\NXP\S32DS.3.6.2\S32DS\software\PlatformSDK_S32K3\RTD\BaseNXP_TS_T40D34M60I0R0\header\)
For example, S32K344.h includes all of the header files for each peripheral in a modular way:

Best regards,
Julián