I looked up the fund; it's very risky in other respects. 1/4 of its bonds are junk (BB or lower), with most of that C-rated. That is the reason for the fund's high return since inception; it wasn't around when junk bonds got killed in 2008, and when they did well in 2009-2010, it shared the returns.
I've looked at past data and MBS bond funds didn't really take a hit even during the housing crisis
This depends on the type of MBS. Most MBS funds hold GNMA bonds, which are guaranteed by the government, and they did fine in 2008; the non-guaranteed MBS were the "toxic assets" that dominated the crisis.
Also, although the fund is considered "intermediate-term" by Morningstar, that is based on its long-term holdings; the current 2.3-year duration is consistent with a short-term fund. For your time horizon, you do want a short-term fund, but also one that is well diversified; Limited-Term Tax-Exempt would be a natural choice for a taxable account if you are in a high tax bracket, or Short-Term Investment-Grade if you are in a low tax bracket or the fund is in an IRA.