vtml in audition text to speech?

I have been playing with Generate Speech in Audition CC 11.1 for the Mac. I am running 10.12.6 on a MacPro. Many of the Embedded Speech Command described in the Apple Speech Synthesis Programming Guide don’t seem to work—or I don’t know enough about the coding to get them to work. But are a few that do work:

slnc: does work well to insert silence. The format is [[slnc xxx]] where xxx represents the length of the pause in milliseconds. I find [[slnc 120]] works as a slight pause while [[slnc 300]] is good to separate sentences. I’ve gone as high as [[slnc 650]] in some dialog.

rate: is very good to slow down a few words or a single word for emphasis. [[rate xxx]] where xxx is words per minute. Here is an example: [[rate 120]] He [[rate 158 ]] is the victim. This elongates and emphasizes “He.” Once it is used it must be cancelled by a second rate command to return to the normal wpm. In this case the wpm set in the Generate Speech tab was set at 158.

volm: Initial volume setting is determined by the setting in the Generate Speech tab slider and volume without any specification is determined by that percentage. The code [[volm 0.x]] setting moves up and down from 10% to 100%. The form is [[volm 0.x]] where x is an integer between 1 and 9. It also works as 1.0. The code must have the 0 before number as in 0.7. Partial fractions such as 0.75 are not recognized. The setting 1.0 is higher than the 100% set in the Generate Speech tab. Depending on the voice a 100% setting in the tab corresponds to about [[volm 0.9.]] The volume setting is not just for the next word but stays in place until another [[volm 0.x]] command is given. I have not found that [[volm + 0.1]] or just [[volm +]] works on my machine. It is supposed to increase or decrease relative to its current value, but no go for me.

pbas: (pitch modulation) works but varies depending on the voice chosen. The form is [[pbas xxx]] where xxx can have a low of about 45 and a high of about 350. I find that a return to the normal pitch varies by voice but is generally within the 100 to 150 region. Since I an using this in Audition I find this easier to use Pitch Bender on the actual file.

emph: The format here is [[emph +/-]] but it does nothing on my computer. I have used other emphasis commands such a vol, rate, and punctuation.

punctuation: depending on the text changing the conventional punctuation often helps enormously. For example add a period in the middle of a sentence, try commas and both semi colons and colons, exclamation points and question marks.

I’d be delighted to hear: how to implement the other listed, OS X embedded [[slnc 150]] speech commands.

Corrected to <vtml_pitch value ="150"> but still no effect