I have had dry suit valves stick and refuse to vent. Mostly when diving small sandy caves in Florida. A couple trips in and out of the entrance restriction in Cow springs and I need to pull the valve off the suit and clean it out before it'll work.
I have had to vent through a seal. If you have gloves over the wrist seal that won't work well especially if they're dry gloves that also have a seal. The air just goes into the glove and gives you Mickey Mouse hands...my wife does it to be funny. If you're wearing a hood you can get to the neck seal by putting your hand in through the hood.
Anyway, it can happen and you need to be able to deal with it.
Needless to say, I use my wing for bc and just put enough air in the suit as to not get squeezed to death.
I have had to vent through a seal. If you have gloves over the wrist seal that won't work well especially if they're dry gloves that also have a seal. The air just goes into the glove and gives you Mickey Mouse hands...my wife does it to be funny. If you're wearing a hood you can get to the neck seal by putting your hand in through the hood.
Anyway, it can happen and you need to be able to deal with it.
Needless to say, I use my wing for bc and just put enough air in the suit as to not get squeezed to death.