That is what is cool about personal experience... it's so "personal".... lol. I have tried thinner strikers. I used them for years because it was "period correct". When I moved to thicker pieces, it was like... "Why didn't I do this sooner?" I find thicker to be much easier. It's like the great knife debate... thick or thin? Just do what you do and have fun.
I don't thing Talfuchre is set up for advanced heat treat, so he has to stay simple. For a non-crucial item like a steel striker, heat and quench is fine.... but a few hours in your home oven at 350-375F would help reduce the risk of breaking.
Edit to add: LRB, I just saw were you said 1/4" is about the max you would go.... that is what I am talking about when I say "thick"... right around 1/4" not much more, not much less.
Rick