In ArcGIS Pro you can set up a series of desired map scales that allow you to choose a scale from a list (see Map scales and scale properties—ArcGIS Pro | Documentation). Only scales that appear in this list can be used as stops on the scale-based slider control (see Vary the size of symbols by scale—ArcGIS Pro | Documentation). Our company provides layer files that make use of this function. For example, we have layer files in which the scale stops are defined as follows: 1:10,000, 1:25,000, 1:50,000, 1:100,000, and 1:250.000. To ensure that these layerfiles are displayed correctly by all our users, every user must have these scales in their list. If a users does not have specified scale (for example, 1:25,000 and 1:250,000) in his/her map scale list, the symbol size defined for this scale in the layer file is simply ignored.
Currently, the only way to do this is to export and share a scale list and then ask all users to 1) import the list and then 2) set it as the default for all projects. Due to the large number of ArcGIS Pro users, this approach isn't really feasible.
The list of map scales is stored in ther user.config. Here is an excerpt:
<setting name="StandardMapScales" serializeAs="Xml">
<value>
<ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<string>1000,</string>
<string>5000,</string>
<string>10000,</string>
<string>25000,</string>
<string>50000,</string>
<string>100000,</string>
<string>250000,</string>
<string>500000,</string>
<string>1000000,</string>
<string>5000000,</string>
<string>20000000,</string>
<string>100000000,</string>
</ArrayOfString>
</value>
</setting>
From a technical standpoint, it would therefore be possible to modify the user.config file for all users using a script. However, this approach would be highly prone to errors.
What I would like to see is the ability to set the list of standards map scales company-wide using the application settings (Application settings available for administrator control—ArcGIS Pro | Documentation). This would ensure that all users have the same scale levels. In Germany, for example, 1:25,000 is a common scale. I’m not entirely sure why Esri sets the default to 1:24,000. There is also no default scale defined between 1:100,000 and 1:500,000.
