There are others here who can probably answer better than I, but I'll chip in with what I'm doing. It might or might not be the best advice. I have a zone vi cold light and do not have a variable timer or variable control. Mine has the original light which does not have much green in it. If yours has a V54 bulb it will look turquoise or almost aquamarine color. Mine looks white. The v54 bulb, if I understand correctly, will work with standard VC filters.

There were several variations of the cold light head. Mine has a separate power supply unit. I'm assuming you have that? It contains the high voltage transformer. I can't tell from your post if you've turned your cold light on or not.

The cold light has a photodiode in it to monitor the brightness. That's the socket that would attach to the variable timer. I took mine apart and monitored the diode resistance very carefully ( with a small series resistor so as not to run too much current through it... depends what kind of ohm meter you have. ) What I found is this:

The brightness increases for the first 20 to 30 seconds, then levels off at a very stable level for several minutes, finally falling off very slowly after that. As the tube warms up, from use and from the heater, this "warm up" time becomes less and less. What I do is before each exposure, I hold a card under it for 30 seconds. This way all my exposures start at the same brightness level and they are completely repeatable, even in different sessions on different days, different ambient temp, etc... I'm pretty sure 20 or even 15 seconds would be fine after warmup, but I've been using 30 for so long now it's just a habit.

As for VC paper with the original bulb. Mine has A LOT of blue light, and not all that much green. So I do all my prints using split grade, with a green filter for the low contrast and a blue for the high. I've read that normal VC filters work but that they can be frustrating to use because the difference between the different grade filters are not even. I decided not to buy them and to go with the split grade approach instead. ( Lots of info here on APUG about split grade printing ). I like it a lot and am glad I'm doing it... It's getting to be second nature.

I was just about 30 years to get to have a wet darkroom again too... just started up again about a year ago! Have fun!