Store Transcoded copies

I would like to have my transcoded copies kept around for awhile. I am trying to sync my daughters' phones (iphone5 on both) and it is having to transcode the movies again because I waited a couple hours in between the syncing of the two devices. Hard drive space is cheap, please have a setting that will store the transcoded video next to the orginal video so that if I sync to a similar device I don't have to transcode again.

https://forums.plexapp.com/index.php/topic/78064-actually-keep-transcoded-tracks-why-transcode-again-on-second-play/

Lets keep things together :)

Early 2021 clean-up: duplicate