The H1 tag is hard coded into the output within the plugin. This should be an option for the user to determine. Webcrashpilot is right… too many H1 hags can be bad for SEO.
I would highly suggest to add an option into the control panel for this plugin to allow user to choose what tag they wish to use. Should be a simple enough option to add.
In the meantime, I am going to look into some option to rewrite the output before it is posted, if possible.