There’s a limitation in MQA which requires us to drop the renderer out of the signal path briefly on track changes. This causes a dropout and breaks gapless playback. There’s not much we can do here and this may never change in Mosaic. We’ve looked into a workaround, but the cost in terms of time and risk is excessive.
If gapless is absolutely critical for you then I would suggest using Roon for playback. The way that the Roon core knits tracks together into a continuous stream gets around this issue.