L1A approval chances if apply after 12 months abroad vs 18 months


New Member
Hi - I am an MNC manager employed overseas, and my company is ready to apply for L1A visa to facilitate my move to the US. However, they believe it is prudent to do so only after I have worked for the foreign entity (in managerial capacity) for at least 18 months. The USCIS L-1 requirement applies a threshold of 12 months with the foreign entity.
Does a longer duration of employment with the foreign entity beyond 12 months improve the chances of approval?
i.e. is there any difference in likelihood of approval based on whether one has spent 12 months or 14 months or 18 months with the foreign entity? Or is the 12 month a binary threshold?