Searched XT and ulduar so if this has been mentioned sorry in advance.
On 25man I can confirm but was told this works on 10 man too. Our guild cleared the trash in the room then we took down XT. Usually we tanked him at the stairs but we were told by a guild member to take him in between the scrap piles on the right side of the room and tank him there. That way when his heart pops out the adds only spawned from the opposite side of the room from the remaining two piles. This gave the raid a lot more time to get the adds under control as they had a long path to the boss.
So
--------------------Stairs-----------------------
pile of scrap --------------------pile of scrap
spawn point -------------------- ( no spawn)
-
---------------------------------------tank boss
-
pile of scrap --------------------pile of scrap
spawn point -------------------- ( no spawn)
-------------- entrance ----------------------
Hope this helps your progression as it made this fight a bit easier. You still have to deal with noobs not running when they get gravity bombs but heh.
If you tank at the stairs it is a short run from the top two piles and they will also spawn from any of the four piles. Quote from Stratfu "They spawn in the corners, similar to Noth's spawn or Vashj's adds. They can and will spawn from all four corners. "
So tanking as listed above will only activate the opposite spawn points. This is not supposed to work this way from all the guides I have found so I hope this helps you all out.