This is 100% for the win. A byproduct of burning any petroleum distillation/natural gas is water vapor. Natural gas, propane, butane, everything.Condensation comes from burning propane. It off-gases water vapor, but so does every other gas you could heat with. Butane, natural gas, etc... Just a byproduct of burning. Venting fixes this.
I experience it every time I'm in the blind. Have to leave a window open to let the water vapor go away.
Bought one of the blue flame propane heaters once to help heat the new shop before putting in a central heat unit. Forgot to turn it off when going to the house. Next morning it looked like a tropical jungle with all the water dripping off of the red iron of the shop.
Never use a swamp cooler either in a shop. Every tool that is owned will have rust on it.