Yes, hitting Escape is how you exit your floating selection without stamping it down. If you need it back at some point you can hit Shift Escape.
How the lasso/cutter/floating-selection stuff are working is of course done with intend. It is supposed to work in the most effective way. You might not agree, so I am super interested in how you would you like it. How would it work, if it was completely up to you?
Thanks a lot Sam!
Best,
Niels