Thanks to both of you for additional insights.

My client accepts that he has to file joint in Minnesota but his issue is that he is effectively paying higher tax in Minnesota (tax rate is higher) due to the manner Minnesota calculates the proportional income and proportional tax . From what I can tell, the Minnesota resident is being taxed more because of the much higher VA spouse's income

VA portion of income is much higher and that gets included in "initial" combined taxable income which is the starting point. The proportion of MN to Total is arrived at and that "ratio" is applied on the tax at MN rates on total income. That works out to be a significant difference because the rate is higher in VA.

I hesitate to get fancy and attempt part year resident in MN and manipulate from and to dates to get around this

Client is reasonable though not thrilled that he is sort of paying a penalty for one of them being a Minnesota resident full year. 

I could attempt sneaky methods but one would be blatantly misstating status on the face of MN return where it simply asks for your federal filing status.

Is "suck it up" the only way if one does not want wish to explore a gray area of a) playing with dates b) declaring incorrect status in MN return