I fly from an airport where for many very good reasons we only launch to the West. Yet in the winter we have many days of Santa Ana (strong East winds). The operators of this airport have 30 plus years of experience with downwind takeoffs. I personally have flown take offs with paying passengers in a 2-32 or G-103 with quartering tailwinds of up to 26 knots, any higher than that I let the owners fly. After some number of these launches they really become a non-event. I have flown take off's with an ASW-24 or Ventus 2c with up to 18 knots of quartering tailwind as do the other private pilots.

Maxims while useful have limitations. Pilot need to be able to fly the conditions given.
The most important thing to do when flying in challenging conditions, set the controls for the wind before the take off roll, i.e., if you have a x-wind from left before the roll begins put in right rudder keep left wing low

Experience of the operators and pilots makes a big difference.
On Thursday, April 19, 2018 at 8:00:25 AM UTC-7, Dan Daly wrote:
Good airmanship says you shouldn't launch with a tail wind or even a moderate crosswind, and that is doubly so with an older generation open class glider (and doubly again if you are relatively inexperienced). You can usually get away with it - for a while - but eventually it will catch up with you.. At the pre-SSA Convention safety talk, one phrase really hit home. Burt Compton said his Dad told him "In aviation, anything you do for convenience jacks up the risk." (I think I wrote it down correctly). At my home field, I have come to the front of the launch line and looked at the windsock, and hooked up to the car and taken the glider to the other end, when I see a tailwind (followed by a safe tow). You shouldn't accept a launch with a slight downwind component which has developed since morning launch direction was decided... Granted, I fly a 55, and standard class gliders of that generation don't handle tailwinds or quartering tailwinds very well (and my previous Austria SH-1 was the same), and I don't have negative flaps.

I realize it is a PITA to pack everything up and do the 'march of the elephants' to the other (correct) end (and in some circumstances (large contests) it may not be the best choice, but casually accepting that you will, in the future, choose to launch downwind is opening one of those holes in the "Swiss Cheese Model of Aviation Accidents". Some of the holes you cannot close; the more of them that "... jack up the risk..", the less safe you are.. Especially in an early-generation open class glider.

I wish you safe flights and much enjoyment in a beautiful glider.

Cheers
Dan