Let's get a few things straight here about dosing and other issues using AD substrates.

Water changes/EI/ADA.
Both suggest large weekyl water changes. Powersand nutrients are removed as well that leach, and they do, into the water column.
The testable levels might be much lower than EI, but...the algae are not limited by this nor any tank with a substrate based fert, the plants act as pipes leaching things out into the water column as does the Aqua soil cap.

ADA AS is clay and have nutrients embedded into the layers of clay, these layers are much smaller and much less diffusion occurs out of the grains.
Hard gravels etc have larger pores than the clay. Thus they leach much easier, like PS.

So ADA AS last longer, but has less nutrients. But if you have 12 liters of ADA AS, vs 3 liter of PS, obviously over time the ADA AS will have a fair amount more nutrients.

ADA AS has nutrients also.

Now dosing the water column vs someone who is forgetful and cannot for some reason not do EI: you still need to dose K+ and traces..........so what is the difference if you add P and N as well?

You still do large weekly water changes also right?

So the only difference is using EI vs ADA is the cost of the ferts and adding 1-2 more items, KNO3/KH2PO4.

The rest is still the same.
But this time you do not need the power sand nor pay 20$ for diluted ferts in a little ADA bottle.

The other thing, you get better growth with EI and ADA AS vs ADA AS and PS/ADA liquid ferts.

Regards,
Tom Barr