Happy Thanksgiving to you also!
The lactic acid bacteria (LAB) only metabolize a few gravity points of sugar into lactic acid -- near 100% of the LAB fermentation carbon utilization produces lactic acid. Lactic acid production will stop once the pH drops to whatever inhibitory level the LAB strains in your SCOBY can tolerate, typically around 3.0-3.5. This lactic acid will remain indefinitely; it won't mellow. Lactic acid is a smooth sourness.
Yeast metabolize all the remaining sugar into ethanol and carbon dioxide. You can monitor the yeast fermentation in kombucha the same way you do with other fermentation, by measuring change in specific gravity. It should probably finish around 1.000-1.005.
At room temp, acetic acid bacteria will metabolize ethanol into acetic acid as long as there is oxygen present, increasing the acidity. Acetic acid is more sharp, with the distinct pungent vinegar aroma and flavor.
I'm not sure what your process is, but generally the issue with bottling too early is that there may be too much sugar left for the yeast to ferment. Excessive fermentation in the bottle generates excessive carbon dioxide. With ~4 volumes of CO2 or greater (over 50psi at room temp), the bottle may gush when opened, or may explode causing a "bottle bomb". Each gravity point generates approximately 0.5 vol CO2 plus there is some CO2 already dissolved in the kombucha.
Hope this makes sense.
I just don't want to hear about explosions.
It's normal for repitched cultures to adapt to your brewing conditions, especially mixed cultures. Optimal strains will dominate and genetic drift occurs favoring the speedy and more acid-tolerant.