Video stabilization always incurs some amount of cropping. The stabilizer needs to "move" each frame in order to create the stable effect. If we didn't crop then this "move" would result in empty regions at the edge of the stabilized
result. Every stabilizer product does this.
That said, the amount of cropping is a parameter that can be adjusted. More cropping can allow for a more stable path, but downside is, well, more cropping. We may evaluate changes to this parameter as the product evolves.