Wanted Spotfire CustomExportTool in its own menugroup

Now we would like to put our CustomExportTool in a CustomMenuGroup, like we do for all our other CustomTool's.
But the Spotfire API does not seem to have the option to include this CustomExportTool in a separate menu group, as it has for CustomTool.

More technical explanation :

We have a number of classes derived from CustomTool<TContext>
using the constructor
protected CustomTool(string menuText, LicensedFunction requiredLicense, MenuCategory menuCategory);
leveraging the last MenuCategory parameter to put our custom tool in a separate menugroup,
and this works well.

Now I create a class derived from CustomExportTool.
I am now looking for a similar function with a similar MenuCategory parameter to put my new class into a separate Spotfire menugroup, I can't find it.

Why does the Spotfire API not support this ??