Bob that is what I was trying to elude to as well.
Hi Mark, to be honest I only read the first three paragraphs of you previous post as it seemed you where on the 'make it yourself' bandwagon.
Now that I read the whole thing I see you had pointed out the listing issue.
However there seems to be some descrepancey
It is my opinion based on the definition in 411 that we need a power supply that is listed to supply LV lighting. We do not need all the parts from one particular manufacturer.
leespark If you follow the letter of the code and listings I think you have a problem.
Two listed for the purpose LV lighting transformers could be rigged to provide a 24/12 circuit on your 8/3 but that will likely be a violation of 110.3(B).
I think it is likely that you will need to run new cable to the fixture.
Also considering the transformer is in the basement and the tracks on the first floor ceiling it is likely that 8 AWG is to small for the job. If you plan on loading each circuit to capacity you
will have noticeable voltage drop.