Jonathan,

I've successfully used register balancing in Synopsys DC since about
eight years ago. In order to notify the other end about when there's
work to be done, it is often a good idea to pass a synchronization
signal (e.g. data valid, deasserted reset) through the pipeline as
well.

Don't forget your post-synthesis verification though (gate-level or
formal). We never completely trust the tools, right?

Regards,
Marcus