I reckon the "jettison all" button should be a double press, like dropping out of SC at speed. That should prevent 99% of these accidents.
If that works the same way the "emergency stop" button does, it probably isn't going to be much use.
I couldn't count the amount of times I've seen the "too fast for normal cruise. Press twice for emergency stop" message WHILE the SC dropout animation is happening.
At first I thought, maybe, I was accidentally pressing the "exit SC" button twice or something but, after a bit of deliberate experimentation, it seems that it just flat-out doesn't
need the double-press to do an "emergency stop" at all. [where is it]
Most common scenario is that I'll be landed on the surface of a planet, I'll take off, realise that my destination is obscured by the planet, jump to SC to leave orbit, get to a point where I can see my destination and then I'll have a brain-fart and hit the SC button again and I'll
immediately do an "emergency stop".
But, erm, yep.
Don't even think I
have keys assigned to any of the "drop cargo" functions.
If I want to do it, I can do it from the right HUD.
And it's not easy to do
that accidentally.
*EDIT*
Are we sure the OP isn't carrying anything corrosive and his problems are the result of corrosive damage to the cargo hatch?
He seems to be having this problem a helluva lot.