Yes subtitles can be downloaded using the extraction method.
Enable via Settings > Advanced > Extractor Subtitles
Then enter the url of the iplayer page you wish to download the video from in the "Enter (or Drag and Drop) .... " field.
Various formats and sources will be displayed, pick the one you want and it will be downloaded along with the subtitles if available.
Thanks for all you help in the past.
Is it possible to download subtitles from the BBC using JMR