Rares are hidden when 'show_all_transmog_rewards' and 'hide_done_rares' are enabled even if there are unknown transmogs for other characters.

Is there an option to show these rares without enabling 'show_completed_nodes'?

You are right, but I farm rares with 4 accounts simultaneously. My main character is flying in full screen and the three other characters are following. I use handynotes on my main character to see whether there are rares with missing transmog for all accounts.

most transmog is soulbound. you cant farm it with one char to get transmogs for another.

this feature would only be usefull in the next expansion where transmog is learned no matter which class dropped it

After talking to @zarillion he decided that we will look into implementing that in the next expansion.

if you really need this feature now you can edit the code of the Transmog:IsObtained() or :IsLearnable() function in core/rewards.lua as a workaround. this might get you what you want.

Yes, but it would be nice to use the plugin in account mode to show rares that drop unknown transmog for my account and not only for the current character.

If you have enabled 'Show unobtainable transmog rewards' and 'Hide rare if all rewards known' the rare is hidden because your current character is not capable of learning any more transmogs from this rare and will be considert as "all rewards known".

Thank you ;-)