debt-to-income ratio back end question home purchase?

I have student loans and I am debating between paying $3,000 for 10 years at a rate of 3.06% or to do $2,200 for 15 years at rate of 3.41%. I believe my mortagage payment estimate with loan and interest at about $1660, home insurance $200/mo, property tax $400/month so total home expenses at around $2260/month. My monthly gross is around $12,000 and I know they want DTI to be at 36% or less if that is the case I have to do the student loan refinance rate of 3.41% at $2,200 for 15 years. I am really interested in doing the $3,000 for 10 years at rate of 3.06% however the DTI back end would be at around 43%. how important is this DTI? would keeping it at 36% just give me better interest rate on the home and loan acceptance and more loan options offers?  Thanks