I’m not sure what your question is… Are you asking if you can deactivate the WPSSO JSON add-on, edit a post, then re-activate the WPSSO JSON add-on? Sure, you can do that, no problem.
Yes, you can use both the WPSSO JSON add-on and Yoast SEO at the same time – there are no conflicts, aside from some setting changes that WPSSO Core might suggest in the SSO notification area (ie. unchecking the Yoast SEO Facebook and Twitter options, for example).
Note that WPSSO Core Premium also includes an integration modules specifically for Yoast SEO, which allows WPSSO Core to read the post/page meta from Yoast SEO and use the values as defaults in the Document SSO metabox.
js.