Advice on international travel while on stem-OPT/H1B processing

[alexpandian]

hi,

my friend is currently on STEM-OPT ext, which is currently running until 2019

Now, she is planning to apply H1B under masters quota this year.

1. can she travel out of US in may-june , with valid OPT, client letter and re-enter without any issues ??

2. if her H1 gets picked this year, can she travel out of US while H1B is processing but has valid OPT, client letter ?? would she face any issues at immigration ??..., i heard in this case once she returns back and H1B gets approved,, she gets I-797B which requires stamping out of US to be done under certain period?? is this true ??

3. if for some reason the premium processing is open, where her h1 gets picked and approved by May, can she travel out of US with approved H1 to be starting only from Oct1st, but has valid OPT, client letter ?? can she return back by July without H1B stamping done since H1 does not start until Oct 1st ??

appreciate your response.

Thanks