Even at 400, its not hard. Only needs 410-420 delta mods to get A rewards in Solo or Pinnacle as long as you use the player stakes (no HUD, no starting ammo, brawn). Do a practice run, see what your score is, and what score is needed to complete the A reward. Then scale the mods or tactic to optimize the run (faster). Time scoring matters, its not just beating the timer, every second is calculated into the score multiplier, so the faster you go the more % boost you get. Up to 15% maximum. Fireteam Ops scoring is bugged and just should not be played if you value efficiency. In order to complete you have to run a larger delta, and farm adds before killing the boss, since enemy kills are a majority of the scoring in Fireteam Ops. I have been solo farming Pinnacle Ops for gear after 400 mostly, because the loot pool is far better than Solo Ops. Im not really farming for power level, but to get better drops on useful weapons and armor. Solo and Fireteam Ops share a loot pool. Techsec armor is useless if you are not using kinetic weapons, Bushido is helpful if you are running Brawn, and the weapons in Pinnacle are better. Plus, if you used Solo to get up to 400, you already have all of the good rolls that you need.