In Reaktor 5.9.2 a new automation ID tool was added that allows one to send VST parameter data to an automation parameter.
Unfortunately, just setting it up 'off-the-shelf' doesn't give very good results. It looks as if the data is scanned at a very slow rate.
I don't know if it is the DAW or the VST that controls that rate, nor how to optimize it.
 
Here is a graphic example to describe the issue.
 
Inside Sonar is a Reaktor ensemble that sends a sine wave LFO output at an adjustable rate. I can vary the LFO frequency and the sample rate (which is 10 Hz and 400 Hz in this case).
 
I sent the data as VST parameter automation and on MIDI out and recorded both.
 
You see the MIDI data is very good, while the VST data is very poor.
 
Any thoughts?