Oh, it's a she, and thanks for the accolade, deserved or not.
Hi Op, did you do your thing with a professional guidance? Because my quandary is why you've changed your status from L-1 to L-2 so abruptly, when both you and your spouse could have been on L-1 concurrently? And why do you have this love-hate-love relationship with your original L-1 employer?
Whether you can work legally back to your original L-1 employer before the L-2 based EAD issuance is not explicitly allowed by law, but what's interesting is that, Section 245(k) of the Act will protect you from an 'unauthorized employment of not more than 180 days' whenever you file your AOS application later down the road.
Your prospect of a foreign travel based on your passport-stamped L-1 visa (though still valid) should be done with extreme caution - it may slide through or it may not. How up to date the CBP's database as to your change of status on US soil (from L-1 to L-2) is everybody's guess. In case it's updated, you'll be denied entry for L-2 visa consular process back to your home country.
(Just an opinion - take it or leave it).
"The letter of the law is a sword that killeth; its intent is a spirit that giveth life." (Justice Holmes on 3 Cor 3:6)