You do realize that EI is a specific fertilization scheme with substances in different ratios than PPS-Pro right?
EI is not a scheme of dosing ANY fertilizer. It is a scheme for dosing the specific fertilizers specified by the recipe. PPS-Pro contains other compounds as well. You can easily unbalance the aquarium by dosing PPS-Pro per EI.
My two cents.
I think you are exaggerating a bit bro!
Nothing wrong would happen, nothing good will happen.
To be able to harm your livestock with ferts, you really have to overdose a lot.
If you go on vacations just lower the amount of light by raising the fixture and or shortening the time it's on and don't have them dose if you are using EI.
Plants are red because they are red, getting plants that are like that is key and a good amount of light. The rest is like talking about magic. I know what you mean by no nitrogen but its not just nor dosing nitrogen all the time, it's a "show" technique.