[Ray]

I believe you're "overthinking" this.

1. Just because it looks like the pebbles are dry doesn't mean they are totally so. There is a gradient, not a step in moisture.
2. In order to increase the height of the visibly wet column of rocks, shorten the distance from the top of the reservoir (the holes) to the top of the pot.
3. If you don't like the drying rate, increase the humidity in the area, don't water more often.
4. Root cells grow in a manner that is tailored to the environment they grow in. If that means submerged in the reservoir, they'll be fine. The only caveat being that if you keep the plant too cool, you might end up with rot, but that's from temperature, not water.
5. Having the reservoir be totally full or maintaining it at half depth or less - or making it shallower by drilling the holes lower - doesn't appreciably change the root environment. Watering every two days is probably overkill.
6. As long as there is water standing in the reservoir, there is no urgent need to water. You can water more frequently than that, but as I said, it doesn't make that significant of a difference to the root zone.