Just a heads up for those that may not have heard about it (like me until a month ago) about a somewhat-recent stomp FX for simulated guitar amp feedback.
Provided you want that sort of thing, the  not EH, but Digitech [/edit] FreqOut is actually pretty good when used properly. Definitely worth an audition if you could benefit from those sounds at moderate levels and/or thru amp sims.
It can be thought of as being to real amp/guitar feedback what the nicer Hammond/Leslie sims are to the real thing…never as good, but way more practical and close enough when used properly…
 Forgot to add, is anyone aware of a plugin that does this?