I'm sure at some point more flexibility will be introduced.

They're the advertisers' ads. They're paying for them, so I doubt Google will ever let publishers mess with them more than we can now

But like I said, as soon as they do some idjits would slap three of them in a row above the fold on their WordPress site and drive fake traffic to it all day long.

Parameter Description & Examples

google_ad_client Required
Your publisher id, should be in the format "ca-pub-#*$!#*$!#*$!#*$!#*$!"
Example:
google_ad_client = "ca-pub-123456789123456";

google_ad_height Required
Sets the height of the ad unit in pixels.
Example:
google_ad_height = 250;

google_ad_width Required
Sets the height of the ad unit in pixels.
Example:
google_ad_width = 300;

google_ui_version Required
Enables the new custom format
Example:google_ui_version = 1;

google_ad_slot Optional (used with google_override_format)
This parameter is used to specify a pre-existing ad unit from the AdSense UI. It will serve
as the base styling.
Example:
google_ad_slot = "0123456789";

google_override_format Optional (used with google_ad_slot)
If a unit has been configured in the AdSense UI, when this parameter is set to true, we will
override the styling configured in AdSense UI with the UI controls specified in the code.
Example:
google_override_format = true;

google_ad_type Optional
Default requests all available ad types.
Specifies the types of ads which could potentially appear in this unit including text, image,
and html (rich media). To request multiple types separate the types with an underscore.
Example:
google_ad_type = "image";
google_ad_type = "text_image";
google_ad_type = "text_image_html";

google_tl Optional
Default is google chosen/optimized based on unit size
Specifies whether text ads should be organized on 1, 2 or 3 lines.
Example:
google_tl = 1;

google_font_face Optional
Default sets the font face to highest revenue generating font per our calculations.
Publishers should only set this if they really need the font change.
Specifies the font face of the entire ad unit. Options include Arial, Verdana and Times.
Example:
google_font_face = "arial";

google_font_size Optional, incompatible with google_tfs (below)
Default is to set the font size dynamically.
Preferred font size control, as this gives Google latitude to optimize your text ad rendering
over time and maximize your monetization. Valid values are small, medium, and large.
Example:google_font_size = "large";

google_tfs Optional, incompatible with google_font_size (above)
Default is to set the font size dynamically.
Can be used in place of google_font_size, but limits Google’s ability to dynamically adjust
sizes. Specifies the font scale in pixels. Valid values are 10-15px.
This is the “basis” for computing the font-sizes of the rendered ads. It will be used as a
starting point for computing the font-size of the different components: title, body, visible
URL, etc. It is not guaranteed that all/any components of the text ads will use this fontscale.
Example:
google_tfs = 12;

google_color_link Optional
Color of the clickable ad title, should be specified as a hex value.
Example
google_color_link = "#0000FF";

google_color_text Optional
Color of the ad text, should be specified as a hex value.
Example
google_color_text = "#000000";

google_color_url Optional
Color of the ad url, should be specified as a hex value.
Example
google_color_url= "#008000";

google_color_bg Optional
Color of the ad background, should be specified as a hex value.
Example
google_color_bg = “#FFFFFF”

google_color_border Optional
Color of the 1px ad border, should be specified as a hex value.
Example
google_color_border = "#000000";

google_ad_channel Optional
Specifies the channel id to be track with the ad unit. Separate multiple channel ids with
a ‘+’ character like the example below.
Example
google_ad_channel = "1419923234";
google_ad_channel = "1419923234+3536539696";