It's a great tuner, but I haven't used mine as a DI. The manual doesn't say what the input impedance is at the 1/4" jack, but I imagine it's lower than is ideal for most piezo pickups, so the output signal might sound a little thin. Using something like fdeck's HPF-Pre in front of it would be a relatively inexpensive solution to that problem.
However, lots of peple use your LR Baggs box with success on DB, so you might as well try what you already have, especially if you already have a decent tuner.
Christopher 401T / Gage Realist Soundclip / Fishman Pro-EQ Platinum Bass / fdeck HPF-Pre Series 2
NS Design CR4M EUB / TC Electronic RH450 & Markbass F1 / BFM Jack 112