My employer wants to be go work at an affiliate office outside of US for sometime.

The task at hand might take over an year and will have a managerial role with reportees

I will be a US employee on an International assignment and will earn salary in foreign country and be a part of the their org chart, but I will also keep some of my benefits here in US.

So, I might be paid in the foreign office in foreign currency and back in the US in USD to maintain stuff here.

Once I come back to US, can I upgrade my EB2 to EB1 porting?
Does having ties with US in the 1 year out hampers the ability to upgrade?

Any suggestions will be appreciated.