Hi Jacoby Alley,
I'm not experiencing the latency that you are describing with the various brush tools on CC 2018 (v 19), with the exception of the actual Brush tool. Smoothing is a new feature that comes along behind us and attempts to smooth out our brush strokes. Have you tried lowering the value to 0?
You might want to review your computer specifications to ensure that you more than meet the minimum requirements.
That said, this is a user-to-user forum, so we can't do anything about the software itself. Please use the link below to communicate issues with the program to the Adobe engineers.
Already tried zeroing out the smoothing, unstacking my meticulously stacked groups, flattening portions of my file... nothing keeps this brush tool from lagging about every 45 seconds to two minutes. I bought the box I'm working on specifically to do the job, so I feel fairly certain that's not the issue. I'll ping the engineers as well. Thank you.
I’m sorry to hear that, but that’s a good next step. I wish you the best.