Indeed, your temps are not bad. Typical idle temps ad upper 20's to low 30's so your idle temps are a little high, but maybe you could incease idle fan speed a little and bring them down .. assuming they don't make more noise than you want to listen to. 40c .
You previously said:
fan curves probably play a role in this too.
CPU Fan at 60C is 55%, 70c is 65%.
Case fans
45% up until 55C
55% at 65C
65% at 75c
Obviously I don't know what rpm they are, but assuming fan are 1300-1600rpm top speed, 45% would be about 600-750rpm, so probalby near silent. Most fans don't become audible untill about 950-1000rpm so I was suggesting to maybe increase fans' speed curve a little for better case airflow but little to no more noise.
But honestly, you have done a good job of getting systme to run cool and quiet. I suspect your next build's fan setup will only need a few minutes a couple of times to get it all setup.