The stock silicone stopper weighs 3/8oz (14g). It isn't earth shattering weight but it is a touch portly for its function in life. I started this project as a simple way of cutting the weight down while still plugging the boiler. I've changed scope after deciding that I'll probably never use the boiler to transport water. The new plan? Make the boiler's pour friendlier.
I made the (less than stellar) video below to show a few different solutions I've explored. I'm less than overwhelmed by any of them but I'd say they're a good start. I like the concept of the snap in style spout but the current evolution doesn't perform well when the boiler is full and isn't particularly heat resistant. For the next experiment I'm considering a MYOG stopper spout like you see in the olive oil dispensers at Italian restaurants using the stock plug trimmed way down and some lightweight aluminum tubing. More on that later. Without further delay...