OK, did a bunch of testing today. Turns out, yes, the v3 board can drive all the various strips I had at the fixed speed setting - when the cable run is 2" away from the board - will test a longer cable run tomorrow.
Turns out that particular Pixelblaze v3 board I was testing with had some strange error, the dimmer slider showed 50% but was infact not working. Ended up adjusting the max brightness from 100 to 1, then adjusting the slider, then setting max brightness to 100 again, then adjusting the slider, and it started working.
[ NOTE: I moved the rest of this post to new topics [1] and [2] - @wizard ]