Hi there, I was reading here and there to find something similar to an ES-9, to send cv/gate directly from VCV Rack to hardware gear, when I remembered that both the KeyStep and the BeatStep-Pro have cv/gate outputs, so I tried them out, and here is what I found out.
The process is done sending midi into the device, and getting the cv/gate output from it.
This doesn’t apply to the opposite way, we still need something else (a DC coupled audio interface for example) to send cv/gate into VCV Rack.
Probably to the most of you it was already clear, but I didn’t find anything detailed around, so I would like to share my experience here.
It is possible to send cv/gate directly from VCV Rack to hardware gear using a KeyStep or a BeatStep-Pro in real time, without having the sequencer(s) running or playing it (said a man who is supposed to play keyboards 
).
We need to connect our device to the PC via USB, then, in VCV Rack, we need the fundamental module “CV-MIDI”, so we select the device we want to use, for example the KeyStep, and connect whatever we want (an Lfo, a S&H…any cv source…) to our 3 available outputs: pitch, gate, mod.
Reminder: we need to setup the device with the Midi Control Center (Arturia’s software) to make sure that the device transmits thing as we want it to transmit (midi channel, V/oct, V-Trig, ecc…), and we cannot modify the behaviour of the parameters themselves: the pitch output is quantized (semitones), a gate can be only on or off, and so on. Keep in mind that midi panic button is your friend as long as you are setting everything up 
pitch: whatever we put into pitch, the result will be quantized to semitones…BUT (5th of Beethoven - PA-PA-PA-PAAAAAAA) these devices transit pitch bend informations as well, which is almost not quantized 
(I think that the transmitted data range is divided into small steps that go from -8192 to +8192, so the changes are pratically non-audible). Furthermore, if 24 semitones are not enough, we can always change the range of the pitchbend from 0 to 127 sending a midi command “cc100 0 cc101 0 cc6 [number of semitones] cc101 127”.
gate: nothing to discuss about, it is high or low, easy game
mod: this is the most versatile output, a midi CC, so, in the Arturia’s Midi Control Center we just set CV mod as “modulation” and just plug something into the socket “MW” of the fundamental module “CV-MIDI”. We are able to control this output in real-time.
With the BeatStep-Pro things are a little bit different. I know there are some very nice tutorials on VCV Rack about how to sync the device and map it as a controller, so I will not discuss it as a sequencer or a stand-alone controller (as which I found to be great).
Here we have 8 drum (gate) outputs + 6 cv/gate outputs (3 for seq1 + 3 for seq2). When I first read the manual, I understood that it would be only possible to use the cv/gate outputs with the sequencer. Actually, if you connect everything and give it a try, the BeatStep-Pro in “controller” mode (with cv/gate) works as described in the manual. You hit the pads, and nothings happens.
BUT, also without running the sequencer, those outputs transmit the incoming midi data from VCV Rack.
We need to load two “CV-MIDI” modules, both set to “Arturia BeatStep-Pro MIDI 1”.
Out of the box, “seq1” outputs come from midi channel 1 and "seq2 outputs come from midi channel 2. Be sure to flag the right channel (again, keep in mind that “midi panic” is your friend…).
There are some limitations I have not been able to pass through. But I don’t know midi that much, and so it is for cv. Someone here maybe can give better explanations.
Here we have pitch, gate, velocity. Pitch and gate behave exactly like on the KeyStep, BUT velocity is updated only after a gate (or retrig) happens, so we cannot use it in a continuous mode as we can do for the “modulation” output with the KeyStep. And, as far as I know, we cannot change that output parameter: velocity is velocity…
…and that’s it.
Hope this is useful to somebody.
p.s. I’m going to buy some eurorack controllers (a ribbon, an antenna and a couple of wheels) for our next show, actually my goal to spend money only for controllers and an ES-9 or something similar.
[edit: I thought that the ES-9 could not to work without a PC, but I was wrong. It works, you just set it up once as a mixer on the pc, and it works without it as well].
Everything else would be done by VCV Rack (lfo, s&h, quantizer, ecc…and fx of course 
)
have a nice time
peace
A