I have seen no issues with the increase in difficulty in ESTFs since the launch of Season 6 (And that was solely Donatra's doing.) There is no ISE buff like you say that there is because on the team I run ISE with whoever solos Right Cube still does just fine.
The issue is still Isometric Charges from the Negh'Vars in CSE, however CSE can still be done fast enough with either Chat Channel I regularly use.
Still can't get that IGE Optional tho. That's more or less my fault as I am an IGE noob, even with 4 really good players.