L1B renewal stamp date over 5 years

[psychogenesis]

I came into the US on a L1B visa which was stamped for 3 years on 31 March 2008 until 2011. Then I went to India and got a renewal on 10 December 2010 and the officer stamped the visa until 9th December 2013. My immigration lawyer is telling me that the L1B is valid only for 5 years in total and that I need to file for a L1A amendment/extension by April 4, 2013. I also have the same company filing a H1B.

USCIS confirmed that the stamped date and the I-94 date of Dec 9, 2013 holds good and there are no issues with me being in the US until that time. I do not want to lose out on the H1B which will give me some flexibility, if needed, to change companies.

Questions:

How can I not lose out on the H1B with this L1A amendment/extension?

Have you seen cases where someone has had the stamped date on the L1B visa for longer than 5 years?

[Attorney_23]

In general, a foreign national may only reside in the U.S. for a total of 5 years in L1B status. The individual would then need to leave the U.S. for at least one year in order to be potentially eligible to return in L1B status.