Have 0.63.19 running, one effect with all installed game is: If a mod contains a huge amount of files like 2000 scripts, 1000 wav files the unpack took.
1% per minute, so all installs took over 1.5 hours per mod.......
Thats incredible, no unpacker ever seen is somewhat slow and it happens to .rar and .7z mods. The NMM process in taskmanager runs with only 20% CPU and 200meg of ram, the harddisk only blink few time per second. The more files are in the mod, the slower the unpack up to 1% per minute.
Previous versions did install the same mod packages faster.
Examples: ZAZ animation pack, SL-Working Girls Sounds, Texture Mods
Edit: Uninstall of these mods took the same time, but u can play other games nearby. Tryin to reset Skyrim SE to clean install and hope to next weekend it will be done.