Set separate extrusion speeds for Dual Extruder

[TourniquetRules]

I am trying to print a part with PLA and PVA for support. I find PVA seems to work better if I extrude it slower. How can I specify that Tool 0 (PLA) can extrude normal speed and Tool 1 (PVA) extrude 1/2 speed (or similar)? I see it can be done manually in Simplify 3D but I can't figure out how to put it in the G-code in general. Maybe it doesn't need to be slowed down but I can't load it without slowing the extrusion.

Related question 2) Where on VIKI LCD can I slow extrusion for loading PVA or NinjaFlex?

Related but different question: How do I make PVA not be so stringy especially on open spaces of 3 inches where it crosses the part being printed?

Thanks in advance for any help out there.