I did exactly that when I started, but as it happened, both the platforms I used were taken over by II so I ended up on one. The advantage of course is that it's cheaper to use one, only one set of fees. But I was also told that although my portfolio was on a particular platform it was still my portfolio and could not be used by the platform to cover their debt. There may be a delay in being able to get control back, but whatever, it was still safe. Am I correct in this?