I am wondering if I can use either the simple present or the present perfect for the conjunctions: once, when, and as soon as. For example,
(1a) As soon as I save enough money, I will travel around the world.
(1b) As soon as I have saved enough money, I will travel around the world.
(2a) Once you learn how to balance on ice properly, you can skate easily.
(2b) Once you have learned how to balance on ice properly, you can skate easily.
(3a) When they finish the meal, I will wash up and make coffee for them.
(3b) When they have finished the meal, I will wash up and make coffee for them.
Is it grammatically correct to use either tense for these conjunctions?