I've been using my LT exclusively for Bass for 12 months now and have gotten to the point where I don't use an AMP/CAB on stage, unless there is no foldback or IEM available.
the 2.80 update provided the Ampeg SVT Pro model which I have swapped over to. previously I was using the GK800.
Rather than using a cab block, I use an EQ at the end of the chain.
There are some really great Bass information from Dr Tone's Secret Helix Lab (drtonelab.com). Jon Willis has done some amazing work in "normalising" but bass and guitar amps for use with Bass.