just a nitpick but I don't see why you need Lum berry. The most common status that will be directed at Metagross will be Burn (usually from Rotom A). You will always be switching out of Rotom anyway (unless you run Zen Headbutt) so I doubt that Meagross will get statused often. Also Flygon can take Thunderwaves and Heatran can take Toxic (and Will-o-Wisp). Also if need be Shaymin can absorb status as well. I just don't see the need for Lum. Personally, if you don't like LO then I feel that LEftovers could be a better option for survivability
Have a Nice Day!