Yes I think it should pass the first message through.
the fix is fairly simple if you want to manually edit.
Find the file rbe.js in your .node-red/node_modules/node-red-node-rbe directory and fix line 57 to be
if (node.previous[t] === undefined) { node.previous[t] = n - node.gap - 1; }
IE add the -1 to the existing line (which forces the initial value to always be outside the range and thus get sent. I'll fix the node and update it soon.
Fixed in version v0.2.9