placing a
dowell near the rail's fastener to provide some cross grain for the
screws. Anyone here do this as well?

Sorry - forgot to comment on the dowels - if you do end up using this
style fastener, I think the cross grain would be a very good idea, and
possibly some longer screws into a couple dowels just to be on the
safe side. Screwing into end grain, even at a slight angle (as in
pocket screws) is quite weak, in my experience.
Andy