@ashikai
I don’t know if this will work with vimeo, but it helps on my sites when using youtube.
https://support.advancedcustomfields.com/forums/topic/youtube-embed-deffer-loading/
It does give a bit of a boost to page load time, but I’ve never tried it with that number of videos.
You mentioned values that could be added to the iframe to help. With the proper coding you could also add those settings to the iframe using those hooks.
