One of the employers is ready to sponsor H1b for me this year. It will be consular processing. However I may also visit US on L1b visa before october. I want to know if we can do change of status in US with an approved H1b after october (without having h1b visa stamped)

Another question i have is if we apply H1b change of status on Apr 1st, can we travel outside of US After Apr 1st and before Oct 1st without getting h1b stamped.