L1B VISA expiry and GC processing

[thums123]

Hi,

My current L1B is expiring in June 2012 and my I-94 is valid till Feb 2015. My employer is going to file H1B this fiscal year and is also going to process GC and are going to submit PERM in April.

Is it recommended staying after VISA expiry before start using H1B from Oct 1st since am worried this might affect the GC processing. Kindly advise if it is advisable to go to home country on L1B expiry and reenter using H1B so that it will not have impact on GC processing.