Whoops, I completely misunderstood that we are using the array type to differentiate between updates and splices. I would prefer that we just always use an object and add a 'type' field that is either 'splice' or 'update' and parameterize on that.  I think this data path could also use some additional comments in slice_bridge_proxy.js to make it clear that we're sending two types of data that we consolidate into a single queue so that they don't get reordered in a nonsensical fashion.