Basement Mix is a Royal Gold coco/Pete blend. It's their middle of the road for moisture retention and amendments.
That's my go to base for seeds, NLS super soil type grows, synthetic, whatever. (I do love the mendo mix too but slowly shifting into the lighter stuff)
Sounds like the blend you might be interested in is the royal gold kings mix. It's their lightest, least amended mix that isn't full Coco.
One dose of recharge a week at 1tsp per gallon. This week was my last week for it as I think it's done growing roots.
As for the burn, I think it'd more of an all around, just a little too much. In my experience with n tox specifically. I get the dark fat leaves with nasty clawing. Which I just had a small amount of weeks 3-5. The PK burn I seen to get more as the tip burning. Which is would rate a 4 out of 10 for severity but it stopped showing up when the sugar leaves started popping. So I think I'm in the clear.
I just know the BAS 3.0 is WAYYYYYY to hot for autos and I think the 25% took it over the edge. That's why I wanna use a1 or 2 cups as an ewc/bio char type application.