Internal processing resolution. The plugin can choose to expose that or a lower res where it'll then internally smooth between values (to avoid stepping). I checked and they have indeed lowered this to 256 steps exposed to host automation for everything. Back in early 2017 the filter and LFO had the full value exposed. Though this would've only been accessible via the automation lane and host-automation based hardware control anyway. I assume the change was made back whenever they did the overhaul of the code to reduce CPU load etc.
Like I said, it caused me to wonder if any of the System 8 controls were using more than 8 bit native, though I doubt they were.
