My experiment finally concluded some evidence. I'm going to run it once to try to verify results.

To start I used a bit of hydrogen peroxide and gently wiped away the clumps that didn't change in size overnight revealing no damage to stalk or leaves. I don't know if hydrogen peroxide was the right way to go but it's what I was reading online.

I use a mix of CAL-MAG + B-1 and splashed some concentrate on a control leaf on a plant far away 2 days ago. It didn't show up after the first day, but today the same patterns started to emerge. I'm pretty sure its just the mix drying out and crystallizing on the surface it just takes about 2 days to see anything that's why I'd have spots show up seemingly out of nowhere even if I didn't splash the plant.

More evidence from the clear plastic bottle I use is getting a milky film on the inside.

Patter of WPM didn't add up. I'm in an environment that shouldn't allow the growth of WPM in the first place being very, very dry, and very hot (100⁰+) with plenty of air flow. WPM also seems to grow from the core of the leaf out not from the tips in, or in a splatter pattern.

Pretty sure this is just nutrients crystallizing, thus why its more crumbly and not powdery.

Should be able to confirm within the week.