It's still 10%, the difference is that by using the LM's instead of point buy, you can take partial negative traits up to their first level without it counting against the 10% limit.
ie. If I get to the optimization point with a 5K character and have Enemy -45, I can make that Enemy -100 and not have the extra 55 points count against my 500 pt limit, but if I made it enemy -200 then 100 of the 155 points I gained would count towards the limit leaving me with only 400 pts left.
-Jackmc