Nice to see a fellow Maryland'er
I agree with Pumilo that if your substrate is wet its because of wicking. I have been doing an experiment
lately exploring different drainage layer options. What I found is even gravels not designed to absorb water (such as pea gravel and marble chip) will wick water. I am assuming your 'growstone like' gravel is designed to absorb water so it will definitely wick.
Fortunately the solution is very doable. You mention that you add water occasionally to your drainage layer. Just stop doing that. Also you will likely want to siphon out any water already in there (assuming you do not have a drain). You will need to disturb a corner of the viv but otherwise it shouldn't be too traumatic to your setup. If it were me I would tilt the whole viv and prop it up at a an angle to get as much out as possible.
Without water in your base or even just moving the water line down as far as possible you will dry your substrate substantially better. Regular misting combined with normal humidity should be fine for all terrestrial plants we are growing. Since you are hand misting if you notice any plant needs more attention you could always mist that plant a little more.
Hopefully this helps.