for me nothing beats alfalfa, soybean meal, kelp, EWC, lime (and a few other things) for veg, and for flowering kelp, EWC, soft rock, lime (and a few other things, lol) and we're good to go!
Just take the time to cook your mix, and you'll notice how far the P source will go, because really, in all the work I've done trying to get a sufficient mix for my needs with as little additives as possible (not small amounts of given fertz, just not many that aren't totally needed, minimalism is a big deal for me and the need to outsource has kind of forced my hand as such), the only problem I've ever run into was availability of P, and that was only at the beginning when my mix wasn't cooked, I now cook my old root balls with soft rock and I pull out media that is super rich and very easy to work with, mix that with your veg mix (minus the alfalfa meal, you could also feasibly remove the SB meal with no real issues, given other variables are taken care of properly).
Don't worry about making your mix too hot, becuase it won't ALL be available right away, and I've also noticed that it's the guano that can make a mix REALLY hot, to the point where it'll be detrimental to your plants. I have yet to burn my plants with kelp and such, and I add quite a bit. I could list amounts in cups and stuff, but to be honest I just 'feel' for it, I add however much I feel like and it always works, but this could be because I've been mixing organic soils for years and have since phased out measuring tools - this is just me, and if needed I can throw out some numbers, measurements per bag (1.5 cuft/10(ish) gallons) and such.
I've even added a pretty heavy amount of vegan fertz in FFOF and it wasn't too hot and my plants LOVED it.
amended mixes with little to no supplementation is the way to go IMHHO.
Also keep in mind that was a quite rudimentary mix, and you can add things that make nutrient availability much higher; humics, bennies, teas....
haha this was meant to be a short post, but I guess I went off....