There is a bit of give and take with the EI. I don't think it will hurt doing water changes every second week.
You should keep on dosing, but be a bit more watchful of what is going on in the tank.
Perhaps you should consider a bit of a blend between EI and PPS. Try dose closer to what you think the plants will need, but still dose a little extra like EI. Overall the key to making it work is just be more watchful on tank conditions and react to them in a timely manner.