Buds like this one will use up over 320mg/L K in my experience. P reduced to around 15mg/L from mid flower.
Is that "15ppm of P" expressed as atomic P, or as P2O5 (as mandated on product labels, at least in the UK & EU)?
15ppm (mg/L) of P expressed as P2O5 ~=69ppm - could this explain the difference between yours and Skybound420's numbers?
This is what I'm currently mixing for myself (comments very welcome): It's based on what a 50% strength GHE Flora (using Soft Water Micro) mixed with pure water would produce. Still getting a lot of stretch at the moment, but my overnight temperatures are lower than ideal (16-17 C) which may be to blame.
N is expressed as N; P as P2O5, K as K2O (in line with mandatory product labelling, for easy comparison).
I've also expressed Si as SiO2, Ca as CaO, Mg as MgO, and S as SO3 (again in line with product labelling, although I don't think this is mandatory.)
All microelements are expressed as elemental.
I use GHE Essentials for Micros (aka B'Essentials, they seem to have changed the labelling at some point for unknown reasons: it's not a B-mix), which is just Microelements - mostly chelated - wthout any Macros or secondaries.
I've recently started using 100% RO water, as we have ~120ppm Calcium in the local water, and bringing that down to pH 6-ish with H3PO4 gave a starting point around 250ppm of P.
(EDIT)
Just to add context, I'm running a recirculating hydro system, (two stackboxes, top one full of LECA, bottom one as a reservoir, submersible low power pump constantly irrigating the pebbles with the nutrient mix). This is running in a tent, with thermostatically controlled extraction and cooltubes - temps kept around 27 at the top of the tent.
I try to keep it relatively sterile rather than relying on bennies, so once they're into flower I add a small dose of Peroxide to the res once a week to prevent any slimes/algaes/root-rot taking hold. My thinking is that almost all my N goes in as Nitrate rather than ammonium, as there are no microbes to break the ammonium down.