Syncing via MIDI has always been a nightmare, and that goes for probably all synths I've had (and that is A LOT!) ... the weak point is many times the DAW... they are simply not tight enough... if you connect hardware to hardware it's usually a lot more stable... so if you work with a DAW, and that is how you want to work, do as you wrote yourself: Sequence it via the DAW sequencer, note by note... trying to sync the sequencers (poly or gated) will only give you misery in the long run... so do not blame the synth alone, there is a lot more to it than that.