Remember the juice is only applied in the last 10 days before expected harvest date. That is when most folks would be flushing and using no ferts.
What I found was that it was not a problem of juice and ferts together, as I had to do that when flowering the Haze.
I would not use juice to foliar feed. It would make the leaves sticky, clog up the stomata on the leaf surface, and guarantee sooty mould. Only apply the juice via roots. That is very important.
I use fresh squeezed orange juice, applied within an hour of juicing. The reason to use juice is to help maximise nutrient delivery to the plant in the last couple of weeks flowering. I do not use it in veg.
Here is a link to my thread which explains why I use juice. 420 Magazine ®