PERM pending H1B maxing out

My employer filed PERM in April 2021 and my current VISA is maxing out in May end 2021. I have around 2.5 months worth of time that can be recaptured. I got suggestions from many of my friends not to max out my visa and leave USA and come back when i140 is approved and extension is approved. Can you explain why maxing out visa is bad and how that remaining time(a month or two) could be useful later?

The H1B 7th year extension is easy and easily justifiable if you leave about a month or so in your 6-year max out.

Sometimes, USCIS questions the extension if you do not have much time left and sends RFE. It does not happen always but sometimes.

Thanks, but I was talking about scenario where I would go to India and once I-140 is approved, employer will file 3year extension based on I-140 approval. In that case what good does keeping some time in hand would do?