The trouble is that MIDI doesn’t actually represent tuplets directly, as I’m sure you know: it simply gives each note a duration in ticks, and it’s up to the application that consumes the MIDI file to try to make sense of it. Dorico and Cubase have very different requirements when it comes to the transcription of data from MIDI files, so they cannot easily share the same code. Therefore there will always be a degree of interpretation involved in figuring out what tuplet structures might be used in a MIDI file. There is of course plenty of scope for us to continue improving MIDI transcription in Dorico, but it is just one of many things competing for our limited development time.