Whatever your lawyer is saying is correct. If I140 is approved then I485 can be filed to the Vermont center based on your residence address. If I140 is not approved then I485 has to necessarly be filed at the center at which I140 is pending. Anyway it is good for you because you have escaped the Texas center which is know for its notoriety
PD 06/01 EB3 India TSC
I140 filed 01/27/05 LUD 05/06/05 AD
I485 Self filed 03/27/05 LUD 08/12/05
Wife filed 03/27/205 LUD 06/29/205
EAD and Advance Parole approved for self and wife
Fingerprint Code 3
Self 08/10/05
Wife 05/10/05