Currently neither using the CompEditor or invoking TDF.changeParStyle changes the par style of a sequenced parameter. The former just makes the parameter disappear, while the latter also creates a non-sequenced parameter.
Bonus: Make it possible to programmatically add a parameter to a sequence (I can see currently this is implemented in the CompEditorExt only by increasing the blockSize by the group size, thus consuming another existing par)
Tagging @Ivan