Karabiner allows you to change the default behavior of the volume keys to use quarter steps with the "Fine grained volume controls" option (it simply adds the alt+shift for you). Very useful with headphones that are too sensitive. https://pqrs.org/osx/karabiner/
Yes, all frames will be in memory prior to making the GIF. Probably fine for most GIFs, but if you want to go FFmpeg | ImageMagick | FFmpeg for processing a video, or maybe for a longer GIF, you can use this script to keep only a frame at a time in memory: http://www.imagemagick.org/Usage/scripts/process_ppm_pipelin...
https://www.gwern.net/Lithium