The "consistency" you were seeing was due to the fact that the first six months you only used bleach with no stabilizer. Therefore the FC from the bleach probably dropped very quickly between additions. Once you started using dichlor, you were adding CYA to your water which was buffering the chlorine and building up a reserve. Therefore, the FC would drop much more slowly over time as compared to water with FC and no CYA in it.
One method to use for your Endless Pool would be to do what is recommended for Spa setups -
Dichlor Then Bleach Method. Using that method would allow you to start up your Endless Pool with dichlor and thus add CYA, then switch over to bleach only. You would find the same "consistency" with that approach.
Is the Endless Pool indoors or outdoors? What does it look like? Can you put your specs in your signature? [EDIT] Nevermind that last question, I see it now. [END-EDIT]