Duan'duliir
Devil of Chance
The option of a dexterity boost and the acrobatics proficiency sounds best, replacing the spell resistance, (I don't know muck about prior edition races in MMs*, but the 5e MM doesn't give the Gith spell resistance, so I'd remove it).
At the risk of being incredibly confusing, for the stat increase, perhaps "+2 to Int, Wis, or Dex, +1 to one of the others" (so you can pick +2 Int, +1 Wis; +2 Int, +1 Dex; +2 Wis, +1 Int; +2 Wis, +1 Dex; +2 Dex, +1 Int; or +2 Dex, +1 Wis)
*My experience with prior editions is looking at Wikipedia/FR wiki/Ebberon Wiki and seeing something that looks cool, finding the sourcebook name, and looking at it to adapt it to 5e.
At the risk of being incredibly confusing, for the stat increase, perhaps "+2 to Int, Wis, or Dex, +1 to one of the others" (so you can pick +2 Int, +1 Wis; +2 Int, +1 Dex; +2 Wis, +1 Int; +2 Wis, +1 Dex; +2 Dex, +1 Int; or +2 Dex, +1 Wis)
*My experience with prior editions is looking at Wikipedia/FR wiki/Ebberon Wiki and seeing something that looks cool, finding the sourcebook name, and looking at it to adapt it to 5e.