I use the SLM clock for syncing arps, drum patterns, sequences and tempo based FX's on my external synths (Roland Juno Stage, Yamaha S90, Novation UltraNova and DeepMind 12.) using an iRig 2 as the interface to a MIDI Solutions Quadra Thru, to each synth, on separate MIDI channels per synth.
The internal synth apps (iSem, Moog Model 15) wouldn't clock properly with the SLM clock.
(fluctuating tempos, skipped beats, )
By "solidly", I mean the MIDIBus solved the internal synth's tempo problems from SLM's clock out.
All is good!