Those buffs were at 35k+ when they were W of 18.
IMHO, to get a buff to 35k or even 40k is the most idiotic thing anyone can do. The buff pilot will waste almost an entire hour of his time (and those who he brings along with him), you deprive your team of (in the case of this raid) 10 or so people for that said hour... and all for what? The moment the target country detects a large bar and knows its an HQ raid (and see they at ungodly height) they WILL up in 109g10's with BFG cannons en masse.
The defenders spend 8 or 10 minutes climbing, in this case, 16 defenders. Then they HO the buffs, knowing that this is the way to do get the buff formation down quickly to non-dangerous levels (aka not enough K of bombs to down hq).
So you do the math... 10+ people out of strat effort for an hour or so and dont accomplish nothing vs 16 people that are out of the strat effort for 8-10 minutes and DO accomplish something.
Its just dumb. Get 2 lancasters to 25k and bring 2 escorts, they have a MUCH higher chance of success than a massive-b17 raid with escorts at 35k.
I still say that there should be 10k alt raised fields in the home islands. BOMBER BASES, with only 1 BH, 1 VH, ammo, fuel, no barracks and acks. This way buff raids would be more common, as the buff pilots would take less than half the time to reach their bombing alt (25k). The only problem is, dweebs like those in the above mentioned raid would use these bases to go to 45k. Perhaps HTC should make that above 28k you would not see target, no matter how much ZOOM you apply to the norden laserbombsight.