The ORP value tell you if there is either oxidative or reducing processes that is active. If it is over 0 - the oxidative processes dominate and the opposite if the reducing processes dominate. From the books
These processes happens all the time and it is the sum of these reactions that you see as the ORP potential. In a natural system - you can never distinct exactly what happens. If you in a natural system have an ORP of 450 - IMO - you are not in danger. However - if you in a natural system with ORP around 300 or lower put in a highly oxidative compound like Ozone and the ORP rise up to 450 - you can be in danger because Ozone will break down into oxygen radicals that affect biological life. De facto - Ozone can be dangerous in lower ORP to - if that is mainly the Ozone that is responsible for the ORP value. Therefore - rise ORP slowly with Ozone. If your normal ORP is around 300 - you maybe should rise it to 320 with Ozone and stop there for a while and after that adjust slowly up to 360 - 400 mV.
Peroxide is more tricky - if you add this - your ORP will in the first moment dip and IMO - it is because the H2O2 lose its extra O and oxygen radicals is formed. When they start to oxidize different substances - the ORP will rise but the dangerous oxygen radicals will be depleted. Hence - if you see a radical dip when adding peroxide - it could be to much breaking down to fast. Oxydators is a good tool to note do local overdoses. Often - when you start with new filled containers - you will see a dip and after that the redox potential will rise with time - this is the last time I load my oxydator. Note the daily swings that is opposite synced with the pH.
A closer look. The read marking shows the ORP when my oxidator is empty - no peroxide in it. The dip - just filled with 11 % H2O2 and 3 catalyst. Blue - the redox with 11% H2O2 and 3 catalyst. I took around a day after the dip - after that back to the normal levels. as you can see not huge difference in the ORP with and without 11 % peroxide in the oxydator
ORP is a fruit measurement - you know its fruit but not which type of fruit.
Another experiences - redox probes take some time before they adapt if they are in another solution or up in the air. If I clean my electrode - it will take 2-4 days begore it is in normal condition again.
I do not think you need to worry to much with 3 % and 2 catalyst. The ORP does not have the same importance with peroxide as it has with ozone - IMO
Sincerely Lasse