I'll try to update this.
MOV captures from your Mac are really large, usually. This makes it into a nice GIF with a timecode in the corner.
ffmpeg -i capture.mov \
-filter_complex "drawtext=fontsize=15:fontfile=/Library/Fonts/Fira\ Code\ Medium\ Nerd\ Font\ Complete\ Mono.ttf:timecode='00\:00\:00\:00':rate=25:fontsize=72:fontcolor='white':boxcolor=0x000000AA:box=1:x=main_w-text_w:y=main_h-text_h,\
fps=45,\
scale=1200:-1:flags=lanczos,\
split[s0][s1];[s0]palettegen=max_colors=255[p];[s1][p]paletteuse=dither=bayer" \
output.gif
Filesize is usually half, and looks fine. VP9 would be better, but /shrug.