Amp is after the limiter - so yes - a little, but I only have it inline (between mixer and monitor controller) to stop the worst of these crash screeches - I dont want it messing with normal functioning sounds
Its the feedback destroyer that does the best job but it takes a little while to decide it needs to do something about it and start attenuating the worst offending frequency bands - the one consolation is it keeps on attenuating expecting the feedback to stop - but its looking for high level sine waves - not raw digital clipping.