how do you check for undercutting with a microscope?

[Inkworks]

That actually looks pretty good to me, you've got some EOM going on, and pretty good emulsion bridging between threads. You might try 2 scoop-coats on the shirt side and then 1 on the squeegee side. Remember the emulsion on the squeegee side should glisten and you should not be able to see the any mesh-look in it before doing your final coats on the squeegee side. If you want even more EOM, finish with 2 strokes on the squeegee side, but the pics you posted look alright.

[Frog]

Let's make sure we're talking about the same thing.
The way I understand the process,
interference from the mesh due to not enough EOM will result in sawtoothing, or other deviations from the clean lines and edges of your film positive on your stencil.

Undercutting will make your open areas smaller.

As I said in my first answer to your question, with a microscope, you could probably actually compare your stencil with your film positive to check this.

Kinda' like this: