New employer to file PERM and I-140

Question: My current I-140 with Employer A is valid for more than 2 yrs now. I’m being offered a full time with Employer B who is ready to file for my GC after a year per company’s policy. My current H1B is valid till Sep 2019. 1) How soon or how late should Employer B file for my GC to retain my H1B status beyond Sep 2019 ? 2) Employer B expects me to travel globally based on the project requirement. Is it safe to travel outside of US at this point and for the next 2 years at least ?

Answer: The new employer can do the PERM and I-140 any time before you file I-485. Further, as long as you have a valid H-1B which if questioned shows bonafide employment, you will not have trouble in travelling.