Caerwen

Hello there. After a long break from the bass (and music as a whole) I've picked up the bass again recently. However I've been having a hard time getting motivated to play and re-learn the bass. I am finding myself limited by the whole tuning aspect of it. I am mostly into the harder stuff, namely metal, and most (if not all) of the tunes I want to learn how to play require downtuning. But they don't all use the same tunings, so it gets tricky. Even very often the same band will use different tunings for different albums and even songs. I've looked into the Digitech Drop, which to my understanding would allow me to downpitch from, let's say, a standard EADG to anything from a whole step down to a full octave. Would that be my only alternative to having to potentially get a 5 string bass, or just change to a thicker gage in my current 4 string one, filing the nut, etc ? Also, does the Zoom B1 four offer a similar function via one of its simulated pedals ?