Custom sounds that can be used with PlaySoundFrontend, PlaySound, PlaySoundFromEntity etc… can be very confusing and hard to create, maybe there could be runtime natives for sounds similar to txd?
Something like:
local soundsetHandle = CreateRuntimeSoundset('MY_SOUNDSET');
CreateRuntimeSoundFromAudioFile(soundsetHandle, 'SOUND_NAME', 'myAudio.wav');