I wonder what is your advice to go through real big chop coming in all unpleasant directions when in well over powered conditions?
When I try to slow down, release power then board become quite unstable difficult to control. On another hand going full speed means skipping from top of one wave to another works well but constant speed increase worry me a bit.
Today. Wind gusting 35 knots, 6.2 m2, board 115L,fin 29 cm, me 82kg, chop >1m
The latter is supposed to happen.. it is fun 
Don't sheet out and try to slow, that is what caused the instability. As soon as you sheet out the sail power is no longer holding the front of the board down.
You may also be over finned, most people are when it is really windy, and that won't help
I know it is different for freeride, but as a 90kg guy, on my wave gear if it is 25-30kn I am on 80L and 4.7. In constant 35 (real solid 35, not gusting 35) I am on 4.0 and 75L.
You are fighting volume and sail saize (and probably fin size too) in those gusts man
You are right with right adequate equipment for conditions. When I switched to my son's gear 74L and 5.7m2 I was quite comfortable.
But I wonder what is the strategy to survive in extreme overpowered conditions that all you really want is to reach bank in one piece when caught by sudden wind gusts?
By analogy on the skis there are some moves that allow you to slow down. But how to slow down running windsurfer without loosing stability?
Grit your teeth
Sail upwind (not like you've got much choice really)
Try not to fall off
Slog if you have to
Do not, repeat do not get backwinded... 
That's in ballistic conditions, totally overpowered 40 knots territory though.
In normal overpowered choppy conditions when you fall off pull as much outhaul on as possible, then sail back.
and in addition to nebbs post
If the board won't stay in the water, it is an opportune time to learn how to jump.
Hop, bear away a bit, land. Hop, bear away a bit, land. Hop, bear away a bit, land.
I'm happy to ride anyway anytime. 
Rough n bumpy, slow n tender.. dinner and a movie 1st.. wait you were on about sailboarding right?
Just kidding Mac - but you may get more opinions for your question on the poley forum.
The main element we ALL need over here right now is wind. 
Hope your'e getting some over there mate. Wind that is.
Hope your'e getting some over there mate. Wind that is. 
Oh sheeart! The troll o' the century is back.
Get back under your slimey rock DG. [}:)]
In reality when conditions are getting nasty, most of you brave responders pack their bags and desert water.
Because sailing is about right equipment, nice sunny weather, smooth water and obviously moderate wind in required direction,
Is no longer fun when current is strong, waves unpredictable, wind gusty, boat traffic crazy,
No surprise in time like that i found myself, 1 kite and one windsurfer only left on the water from just about group of 20 a minutes ago.
35 knots with a 6.2 on a 115 l... are you for real dude or dud lol.
try a 80 liter on a 4.7 sounds about right
Mabe its gusts of 35?
You harness lines must be back at the extention travelling upwind comfortably lol
I could only imagine how your battens feel popping in and out on 1/4 sheeted when you come to the conclusion you have to go down wind at some stage !!!
Are you trying to break your ankles >.. please wear a gaff for your own saftey.
Find a big bit of chop and hit it, do a forward loop in the direction of the shore !! Then your home with style! Tell me there is no merit in that!!! He hee.
