[catwell]

Yes, if you assume some of the clients go away indefinitely without giving their share back and you don't have a solution to deal with this, it's a problem.

Solutions are relatively easy on a client-server model (but do you really need something like ITC with a server...?) For instance the server could delegate its part of the interval with a timeout and claim it back once it expires.

If you know you have this model you can find a different way to split the interval to avoid the issue of the linear number of bits. Nodes can split their interval however they want.