Hi Kurt,
You do not specify but I believe you may be referring to the SA2 Breathy Sax and I am not aware of how to edit that type of Voice in YEM.
You can use a DSP effect to enhance the breath sound and one of the best is in Distortion, Multi FX Oldies Delay, since the preset settings give a reasonable amount of enhancement while retaining a good sax sound (better than the default sax IMO). If you want a bit more try raising the Comp sustain from its default of 4, (there is a limit where it becomes too intrusive) and set Output to maximum.
Also fine tune the effect by tweaking EQ in Voice editor. For example at a quick look I used 3.6kHz Hi, gain 12, and 355hz Lo, gain 4 in combination with the preset Dsp.
John