IMO you are being anal about things that don't really matter. Being new to the device it seems like they do though, as I also didn't understand the vapor path at first and thought it required cleaning (it doesn't).
I've owned a VROD for 2 years and never ISO soaked anything. 600-680 concentrate temp, NV SiC dish, some SiC terp pearls. Take a hit then dry swab with qtips, might be a little smoking from the nut, but the concentrate flies around in there and WILL get on the nut. Carb cap also creates a slight vacuum which might add to this. It's a non-issue though. I only take the nut off when I burn a dab on, and then I take the nut and dish off and torch it. Comes off just fine with pliers when the unit is still warm.
I qtip the nut a little bit after a hit, but some probably gets in the threads which causes the little bit of vapor to come off the head. This is not going to alter the experience. Smoking for 10-15 minute after taking a dab? As I said, I've had this 2 years and
never have I seen that. It will let off vapor from the nut for a few seconds, and that's only some big hits. Hard to imagine how there is even enough material for it to smoke for that long.
ISO soaking is the wrong way IMO. You're also worrying about things you don't have to. The vapor path in the VROD head itself will stay 100% clean due to the temperature; it repels the vapor. You need to worry about the dish and that's about it.
Next time your SiC dish and nut are dirty, grab a torch and take them off the head. You should not be cleaning the whole head assembly, especially on a new device.
Yes, it definitely can be a concentrate only device as I've used it for many, many, many grams of concentrates in a 2 year period. I don't even really use flower right now. I'm in the camp that the VROD is the best, as I don't want a ton of different heads, multiple coils, etc. If your tolerance is so high you need a 30mm dish for your size dabs, take a break