You can use all of the same techniques, as long as you're not using WORLDLINE-R or worldline. Change the renderer to CLASSIC and use the settings icon to pick another resampler.
This means you can use the extreme vibrato method, utaugrowl as a wrapper on another base resampler, or resamplers with built in growl flags like Moresampler. If you're using a voicebank that already includes screaming/growling sample, I recommend using tn_fnds or macres specifically.