I have the same issue, but the bottom of my stairs are rounded. Ok, I
can cut boards to fit round, but how do I bend the beading strip into a
tight radius ? I don't think it's possible. What have other people done
in curved areas where laminate/wood butts up with an expansion gap ?

In this case the bottom of the stairs were curved and they'd used cork to go
around the edge of the laminate.

To be honest you could hardly see see it because of the carpet on the stairs
anyway.