LR has always been weak at managing large numbers of presets, and the lack of multiple selection is frustrating. Workarounds:
- To delete large numbers of presets, right-click one of them and do Show In Finder / Explorer. Then delete the corresponding .xmp files with Finder / Explorer. Restart LR. Beware that the names displayed by LR don't always match the .xmp file names (the display name is stored insider the .xmp file).
- To move large numbers of presets to other preset groups, use the fre