Digital BW, The Print

I'm preparing a web submission of monochrome images, and the
submission guidelines require tiff or jpg files with grayscale images
saved with an ICC profile of Dot Gain 20%. I work on a MAC in CS and
have my Photoshop Color Settings set at Working Space = Gray Gamma
2.2. I have a calibrated monitor and print on a 4800 using ABW on
Epson Premium Semi Matte. In my workflow I use a monitor proof setup
(view, proof, custom, etc) with a Dot Gain 20% proof profile. This set
up results in very good screen/printer coordination for me. Here's the
problem I'm dealing with:

The images I want to submit are worked up as described above. The only
way I know to satisfy the submission guidelines is to go back into my
PS Color Settings and change the Working Gray Scale to Dot Gain 20%. I
open the image, disgard the existing embedded profile (GG 2.2) and
then save the image. Now the image ICC imbedded profile is Dot Gain
20% as required. The problem is that the on screen image looks bad,
much darker and more contrast, than the former screen image and print.
This is what the folks I'm submitting the images to will see.

So what am I doing wrong? I don't understand why Dot Gain 20% works as
a proof set up when my Gray Working space is GG 2.2, but when my
working space is changed to DG 20% I get a different on screen result.

By the way, I also have not figured out how to save the proof profile
with my image, so every time I open an image to work on it, I have to
I have to do the proof set up steps.

Help with these questions is greatly appreciated.