I don't accept OpenAI's claim that its fingerprinting is imperceptible to humans.
Text isn't like a video, picture, or audio where there's so much going on that a digital fingerprint can slip through unnoticed by a human observer. You have to change the content of the result in a way that would be directly seen by the observer. Instead of perhaps imperceptibly changing the color or brightness of pixels in an image, it would be more like changing a robin to a bluebird. Most people may not notice but to many, I'm sure, it would stick out like a sore thumb.
Isn't the purpose of LLMs to as closely emulate human speech as possible? This seems like it would be a step in the wrong direction to that goal.
I'd suggest just running an LLM offline at home, you don't even need a supported GPU with loads of VRAM. Most methods run on CPU with GPU offloading. You could run them completely on CPU but they would be very slow. The overall size of the module you can use is dependent on available system memory while the amount you can offload to the GPU is generally dependent on available video memory. I've been using Llama 3 Uncensored Lumi Tess Gradient 70B Q5_K_M lately. It's 50GB and seems to be just about the limit my 64GB of memory can handle.
I'd highly recommend Backyard AI. It's simple to use and is geared towards the use of character cards, with the ability to import SillyTavern PNGs. It's a very simple install. If you have a supported GPU then just enable it in the main settings and set memory to auto and you won't have to think about it again. Then just download a model and character and go. You also have the ability to set it up as your own personal online LLM, available to you anywhere using your account in browsers or mobile apps (they call it tethering). It also has a free/paid online service but you don't need to worry about that, just set it to use your personal computer.
LM Studio is more along the line of the basic prompt/system prompt setup. It's easy to setup and models are easier to browse but GPU offloading is done in "slices" that have to be manually set each time you start a new chat.