I have not been to the springs for a while so I am not familiar with the current situation. I have never experienced any problems while hiking nude other than a surprised expression once or twice. I do avoid weekends. Once many years ago on my way to the springs I dressed on the trail when I saw some rangers approaching in the distance. I wasn't sure of the official stance. As I approached them I could tell one was having trouble with the heat. I offered her one of my water bottles as she had none with her and was dressed in that heavy uniform. She gladly accepted the water and we chatted a bit. I took the opportunity to ask about nudity in the area. She got a wide smile on her face and with a sweep of her hand she said "you can be nude anywhere in this area" I removed my shorts with an approving nod from her. I think she was a bit envious due to the heat and heavy clothes she was wearing. We continued talking a few minutes until she felt a bit better. I told her she could keep the water as I had two large bottles and we went our separate ways.
Another time while hiking out nude I saw someone up ahead of me as I rested at the top of mo fo hill. He stopped in his tracks and glared at me from about 40' away. He took off his pack and I thought he was going to berate me or something by the way he looked. Instead he laid his pack on a rock, took off his clothes then folded and stowed them in his pack. As he approached me he smiled and said it was his first time at the springs. He was from Utah and wasn't sure of the clothing optional status. I relayed to him what the ranger had told me and he was happy to hear it.
I know the map Mike has says no tan lines no problem yet if society seems to be changing a bit regarding naturism maybe some sort of sign at the gate house or trail head stating the usual "Beyond this point you may encounter nude hikers and soakers." would be a good idea. That way those with less accepting attitudes would be forewarned and may decide the trip isn't worth it.
I'd be willing to chip on cost of lumber etc. if others think it is a good idea.