I haven't noticed any type of fatigue, but the synth process is definitely more difficult, more expensive and less rewarding. As I said in another post, I use 2 raw materials to make 1 intermediate material using a synth that is 5 levels above my level and it only gives 200 exp whereas before 1.19, I could do a synth that was 2 levels below me and still get 250-300.

SE just needs to rethink this previous patch on grinding and try to find a middle ground between then and now.