I run the same 3-2-1 ratio and then dilute to my target EC. In my case, that's anywhere from 1.1 in veg to 1.8 in peak bloom.
My bloom booster changes; .5 gram/gallon of
MOAB, or 5-10 ml/gal of
botanicare CNS17 Bloom or ripe (these are complete nutes, I use them to bump ec between change outs), or any of a number of P boosters, used at about 1/2 label strength to start. I don't added much K per se, because I think Jacks has plenty.
I run high humidity (especially for Colorado!), so I run my ec higher than most RDWC growers in bloom, often by 25% or so. My girls look great, no tip burn, grow well and dank. I flush for 8-10 days with 2g/gal of Epsom salts and 1ml/gal of standard sugar. This results in fabulous colour, very smooth smoke, intensely aromatic flavors- and empty inventory, lol