When trying 7.5.0-SNAPSHOT, I found that old form editor seems to have been removed, but in BPMN Designer, when trying to generate or edit forms, it still pop up two form editor selection: "Graphical Modeler" and "Graphical Modeler (Preview)", and when clicking on "Graphical Modeler", following error is displayed:

Unable to complete your request. The following exception occurred: Parameter named 'scheme' should be filled!.