Also, if you are monitoring the plug-in in real time the latency is also a function of your DAW and computer.
And be sure to select your device's ASIO drivers in your DAW.
+1 to fflbrgst
You currently can not aggregate ASIO devices on pc's (with a few exceptions).
You may be able to monitor the PF plug-in thru your DAW in real time with no perceptible latency. IMHO a mixer would be a good investment.
I'm pretty sure since you own the triple pack, purchasing PF2 standard you should still have access to your triple pack.
Whatever you do, do not get the i-Lok version.