Is "Step 5: Grass Cache" supposed to show any kind of progress or activity on screen, or is it supposed to sit at the main menu? I kind of assumed it'd be loading into new areas or something. I also don't see any meaningful disk activity (<1%) or file changes in the SKSE Output directory. (Apart from a couple of INI files that seem to be "touch"ed on launch.)
I left it running on a decent system (5600X, 5700 xt, 64GB RAM, 4TB SSD) for an hour and a half, no changes.