Is the Z2 lamp sufficient to germinate and propagate a 12x28” tray of vegetable seeds in 3 inch pots? Once established and 3-4 inches tall I then transplant outside into my garden.
Yes, the Z2 would be great for that area and task. Just a side note: the more square you can make your grow area, the more evenly it will illuminate your plants, but it will work either way.
Are you growing in a grow tent? This will alter the intensity of light in the outer edges a little bit, since light bounces. This would also create an intensity that is more even throughout the canopy.
The Z2 should be hung at about 2,5' from the canopy for the first couple of weeks. This will create a PPFD (light intensity) of about 200 in the absolute middle and about 120 in the outer edges of a 2'x2' area.
100-200 PPFD is what we recommend for the early propagation, so this would be perfect for your needs.