After a night's sleep, I came at the problem differently. Ignoring the layer question entirely, I created a second, tiny page form (7 x 1) and loaded it immediately after the first page form in the parent's EZ_Loaded event. This second page form is positioned over a blank space on the parent, so while it's present, you can't see it. I can then use EZ_ShowPage in the parent's tab events to show the first page form when layer 1 is selected, and switch to the blank second page form when other layers are selected on the parent form.
This took only about five minutes to put into place and it works perfectly!