Hi!
Firstly, there's no smoke in vapor. It's just vapor. (Small detail but important to the cause...)
Also (wow, I'm sorry) you can't use a Pico with a Subox, as those two things are both mods.
You are using a Subtank (mini Subtank 'tank') ON a Pico mod.
The good news is it's a combination we know and like well enough. I do build atomizers but use plug and play for work, so know I these coils (the replacement atomizer heads)
For me, the 1.5ohm coils are quite weak for such a large tank. These are not designed for high power vaping. They will work best at quite low power (8-15?) watts with the airflow on the subtank mini closed down to one tiny hole (or the minimum airflow).
The 0.5ohm coils are better suited to opening up the airflow and using them at medium power (15-30?) watts.
The problems will be matching the coil/watts/power (recommended rating) to your inhaling style.
If you get the combination out, you will wonder what on earth you are doing wrong.
I would personally do one of these.
1. Use the 1.5ohm coil at 12-14 watts, set the airflow to minimum and inhale into my mouth first (MTL, mouth to lung)
or
2. Use the 0.5 coil at 16-24 watts (maybe starting even lower just to get it going) with the airflow open and inhale to the lungs direct.
The exact numbers come down to personal preference and the top power of the coil might be not as high as the manufacturers say... there are SO many different versions of Subtank coil. I like the SSOCC version. The originals were square and called OCC... not so good i.m.o. and worth avoiding if some shops are trying to pass them onto new vapers.