Problem setting different framerates with FFmpeg map option
-vf does not accept stream specifiers. You can use e.g. -filter:v:1 for that.

However, you need not use the fps filter at all; output -r will do.

ffmpeg -i input_60fps.mov -map 0:v -map 0:v -c:v libx264 -crf 23 -s:v:0 640x360 -r:v:0 30 -s:v:1 1920x1080 -f mp4 out.mp4