If I understand your feedback properly, you only want to show the parent heading tags but not its children headings. Is it ? If so then you can remove those tags from Heading tags option. Say you want to show only H1 tag but not those underneath tags like H2, H3, H4. Then in the option remove those tag.
Let me know if you meant anything else other than this. Feel free to open an issue here https://github.com/dbjpanda/kb-elementor/issues