Cant see the need to leave it for an hour. With grain weights <2kg you can easily move the bag around to ensure the grain is fully rinsed and this will extract most of the residual sugars. I do this and the bag is in the sparge liquid no more than about 10 minutes whilst the 'first runnings' are heating up in the pot ready for the boil. This works for me timewise, and more to the point I still get good efficiency. And finally with such small volumes a kitchen kettle can be used to heat up brewing water, which, in my case, is much quicker than using the cooker hob .