Yolo + SiamMask

Is there a way to provide Yolo bbox detections as input for SiamMask?

Yes you can - I have done the same thing before using the Ultralytics object detection API and this paper explores just that.

Bear in mind though that the SiamMask codebase is not really written with much in the way of maintainability and so is not the easiest to work with. I may open source my implementation of it later on when I have some free time.