A version of LotroPlan that has the post-Mordor stat arithmetic and includes Mordor gear items has been released.
The first post of the forum thread has details:
www.lotro.com/forums/showthread.php?539545-LotroPlan-calculate-stats-amp-plan-upgrades
The download link is:
www.dropbox.com/s/76vt3ny42uxcksp/LotroPlan%203.10.ods?dl=0
My blog post was written for an earlier version of the spreadsheet, but is still accurate. (Let me know if you find things that are no longer correct.)
shadowbanekin.guildlaunch.com/users/blog/2962374/1546818/using-lotroplan-for-essence-gear
If you're trying to figure out which gear alternatives you want and which essences you should use, this is a terrific tool. If you want any help using it, let me know.