When I solo I usually play at 3/8 before incarnate shifted, then 4/8. Sometimes depending on enemy types then I will bump it down. My baseline for all characters at level 50 that aren't Incarnated, is starting with 3/8 doing Unai Kemen's 2nd "Close The Dimensional Portals" mission that has all of the Council mobs If a fresh built 50 can do that comfortably then its a keeper. They do knockback and stun so toggles will drop, and once your detoggled then your dead. I usually on softie characters buy some P2W defense amplifiers to keep from getting stunned. I don't always do it but sometimes. Depends if i feel like spending the inf and the toon is fun.
My toon before the Farsight buff has S/L Def of 19.80, E 17.08. with Power Boosted Farsight: 40.60 SL, and 37.88 E. Add another 5 with Defense Amplifier or Barrier if you go that way. I probably will go Clarion for CC protection. If I get time I'l try to make a video. But it may be a while.