I have an indoor pool room. I'm far from an expert, since I wasn't involved in the design (1972) and this is my first pool, but I'm happy to share my experiences.
I use mine as a winter pool. It spends the summer months cold and uncovered. It has no measurable impact on indoor humidity in that state. The intrinsic dehumidification performed by the air conditioners for the home keeps humidity at reasonable levels. I monitor it with Nest thermostats.
The pool room climate control is provided by 3 vents fed by a commercial-grade HVAC unit which also serves the foyer and a bedroom. This was a point of contention when we inspected the house. It was suggested several times that a dedicated humidity control system be installed.
I like to swim in the winter with pool temps in the high 80's. There is a variable-speed high-volume exhaust fan in the ceiling, and I keep the pool covered when the water is warm. Removing the cover without running the fan dumps huge amounts of humidity into the house. If I'm slow to turn on the fan, even windows at the far end of the house will fog. If the fan is running however, moisture isn't an issue. Even the windows in the pool room itself tend to stay clear. When I'm done swimming, I pull the cover back over the pool and allow the fan to run until the cover begins to dry. When I see it drying, I can turn the fan off without issue.
My biggest challenge may be one you'll never face: cold replacement air. Expelling the warm, humid air is no issue, but the air that replaces it can be. The air stays dry, but is continually cooling. Running the furnace can help a little, but much of the dry, warm air it's producing is expelled without benefit.
I'd be tempted in NM to forego a dehumidifying system and rely on a cover and fans instead. (maybe a fan controlled by a humidistat if you don't want to cover the pool)
