I've tried both blades, they're both very good options and you can't go wrong either way.
YEO is not stiff -- actually it is quite flexible. But there is a difference between stiffness and hardness. Hardness refers to how difficult it is to penetrate the surface wood, while stiffness refers to how much the blade flexes. It is possible to have a very hard blade which is also very flexible, and that is what YEO is.
If you didn't like Goiabao 5, then that's a decent indication that you won't like YEO. Goiabao is both stiffer and harder than YEO, so you could imagine that YEO is a baby version of Goiabao.
Blades like YEO and Goiabao work best with hard tacky Chinese rubbers. Using them with European rubbers feels bad and out of control. If you get a YEO, I would encourage you to try it with Chinese rubbers -- Skyline 2 or Skyline 3 on forehand, and maybe Rakza Z or Hurricane 3 on backhand.
Interestingly, YEO actually works pretty well with Rakza 7. You could put that on your backhand if you want. But it really shines with tacky Chinese rubber.
If you want to stick to softer European rubbers, then you should also stick with the limba-limba-ayous-limba-limba construction which is used by Korbel and Stratus Power Wood.
I want to buy rubbers maybe rakza Z on both sides or use rakza 9 for FH and Z on BH.
Rakza Z is a good transition towards harder rubbers, and it sounds like you really liked the feeling. But honestly at this point you may as well just use Hurricane 3 Neo, save some money, and get a better rubber.
I would stay away from Rakza 9 if I were you. Either Rakza 7 or Rakza X are better.
At the end of the day, the question is: are you looking for a different setup? or another one of the same?