If you have H1B stamped from anywhere else but Nepal, then you don't need it (that's what one of my friend who got his stamped in Mexico experienced). However I had to bear hassles in Nepal Airport when I got mine stamped in Kathmandu. Though I made it through with out any significant trouble, I had to endure some unwanted situation. These folks are big on H1B's because there is a possibility for dollar extraction. I went through line by line of that law and felt that it was designed for people going to Gulf. Still an agent for Gulf employment can get these labor permit in whisk no matter what the working conditions for those jobs eventually  are. But for Most H1B, who have employee health benefit, prevailing wages, and other strict US regulation  have to go and insure with  Bima Sansthan and abide other crap. It's time they modify the law, though the law doesn't say any specifics on H1B the broad generic term "foreign employment" encompasses it.

There is no provision on the law that states that any one going back to Nepal with prior Labor sticker to get new labor sticker when renewing the H1B for another 3 years.

And this labor thing doesn't apply for PR's

I would recommend to obtain it if you want to avoid unwanted hassles. But, if possible, make sure none of these suckers get any ghooos during the process of obtaining certification. And, if any one of you have links to any top journalist in Nepal, please ask them to address the issuue if you encounter any during the process. I like the concept of this labor certification to avaoid Nepalese being exploited abroad, but this shouldn't be means for extra income for these suckers.