Stickly style I want to achieve. My plans also recommends placing a
dowell near the rail's fastener to provide some cross grain for the
screws. Anyone here do this as well?

I think I used the same set of plans, but ditched their fasteners as
described in my previous post. I'd recommend doing some sort of mock-
up or practice piece with those fasteners, to make sure they'll
accomplish what you want. The end cap/cover is easy enough to work
around - I can post a photo of my fastener system and end caps if
you're interested.
But if you try the stock fasteners and they work for you, great!
Maybe the brand/batch I got were bums.
Enjoy the bed,
Andy