I'm sure you are already aware that Valvoline lists the following Subaru CVT applications for MaxLife ATF:
ECVT
iCVT
iCVT FG
Lineartronic chain CVT and CVT II Fluid
Lineartronic High Torque (HT) CVT Fluid, CV-30, K0425Y0710
NS-2
Use it with extreme confidence in these applications so long as you:
1. keep the CVT pan & magnets clean
2. monitor the fluid temperature and avoid overheating
3. firmware updates and TSBs have
been applied
Having said that I can certainly understand why spending a premium on Amsoil or Idemitsu might help you feel better. I've personally used Amsoil in JATCO CVTs but have now switched to Valvoline at $50 CND / 5L due to availability. Both of these options are significantly cheaper than shopping at Nissan.