My opinion is Level 131. This way many Tracery boxes that you open will give Traceries that are good up to level 150 if opened at Level 131+, vs ones opened at 130 which are good to Level 140. Level 131 is also a Reforge point (next is level 136) There is a significant DPS Boost with the new LIs as well. I do suggest reading a guide to learn the ins and outs of the new LIs.
Here are 2 but there are others and videos as well: