Joel Koltner wrote:
(snip)

... I don't think there's a lot left to
do on this particular PCB, but I'm thinking the results are good enough that
it's safe to put the design on a 4-layer boad and see what happens.

Don't forget to put a hole in the layers under the switching
output pads and trace. You don't want a capacitive load on
that node to anything.

--
Regards,

John Popelish