You can just use JACK and connect LMMS as a sequencer. This is my workflow
primarily when it comes to Gigasamples - using LMMS as a
sequencer/pattern-editor only. I'd rather not have LinuxSampler embedded, as
LMMS still lacks internal routing capabilities which makes it impossible for
bussing. And that's really important with huge sessions where a number of
layers play the same sample.