What wattage to start at for my new quantum boards (adjustable)

Hey guys, so I made the quantum leap and bought this:

https://horticulturelightinggroup.com/collections/all/products/320w-xl-qb-v2-led-kit

Anyways I’ve always used blurple lights in my 2x4 and they were never adjustable. Between my 2 300s in my tent they drew 270 watts from the wall.

Between 35-40 watts per sq ft has always worked well for me with the blurples, I went to 50 once and the plants HATED it (did two 450s and went back to the 2 300s) but what about QBs?

Well this board goes from 100-320 and I’ve never had to adjust for wattage before, just height obviously.

I’ve read that veg needs less watts per sq ft than flower, so I’m not sure if I maybe start at 200 watts then adjust the driver to 300 come flower time?

Same with the height. The blurples always just used the 30/24/18 (seedling/veg/flower) height rule and it worked fine.

I guess I could just set the driver to 270 watts (verify with my killawatt meter) like my blurples and use the same old heights as always, but I figured I’d get your guys input and maybe experiment properly.

Any input is appreciated.

I have a 4x2 tent and 3x QB 288s, I kept mine at 110 watts for the first couple of weeks and bumped it up to 140-150 towards the end of veg. I'm no expert but it seemed like plenty of light, there was zero stretch and in fact the plants are extremely bushy. A little goes long way with Quantum Boards. 200 is definitely going to be overkill, particularly in the first few weeks. As far as height, I kept it between 22-25" for veg.