For now it's 32 bit only, VST2.4.

vArranger now includes a powerful virtual synth with SoundFonts support + VSTi (still beta)

My way of thinking is to create your sound banks with some SF2 + some VSTi, Load all from the beginning, and not load any new vsti or samples anymore during the session.

If the VST allows to be controlled by midi on 16 channels, and select sounds by program changes, it's perfect !

I don't like to load VST between 2 styles.
I want perfect sound and styles transition.