Hi Martin,
There currently is no possibility to configure symbols/texts to be placed at intervals on a curve or polygon outline.
The only possible route is through the SDK, which provides the possibility to write so-called Style Converters.
These converters provide the possibility to write your own custom draw logic, allowing for more complex styles to be created. This does require programming, which is maybe not the route you're interested in.
In case you want these kinds of styles to be directly available/configurable from within GSA, I suggest logging an enhancement request through your support channel.
Best regards,
Frank Pistorius