Sounds like you have way more photography knowledge than I do, but here
goes.

I sometimes need to take pictures of small parts. I made a small light box
that works ok for some, but if shadows are not a huge issue I take them
outside and set them on the ground in the sunlight and stand up on top of
one of my jobsite boxes. This allows me to shoot straight down at the
part. Then I use my highest resolution and highest optical zoom to take the
picture. I have several digital cameras, and the one that does this the
best is actually an inexpensive Vivitar HD digital camcorder, but my old SLR
(looking) FUJI does ok too. Mid day is best. Alternatively in the shadow
on the north side of the shop works for some if glare or reflections are a
problem.

If I have to do it indoors I can do roughly the same thing, but I light the
part from an angle to either side of the camera with a pair of 250 watt
halogen work lights.

Instead of trying to macro at 3 feet or closer I zoom from about 8-10 feet.
As long as I get a good focus it shoots pretty good.

I usually get a pretty good shot within 3 tries with one of these methods.