> In addition, for those individuals who obtained treaty country nationality through a financial investment, USCIS may require additional documentation to show that the applicant has been domiciled in the treaty country indicated in the application for a continuous period of at least 3 years at any point before applying for E-1 or E-2 classification.
Plus E-2 visa is a non-immigrant visa, so it doesn't give you any kind of special pathway to green card. Might as well apply for an EBx at the outset instead of fiddling with an E-2 visa.