Can anyone recommend a good feedback eliminator?

Yes, I’m aware that there are hardware solutions (and I haven’t tried any of those yet), but as a musician who travels light (by choice and by necessity), I don’t want to add more physical gear to my rig. Right now I’ve got just a single 49-note keyboard, my laptop, my iPad (for sheet music), my audio interface, and my vocal mic, plus their respective cables and chargers, and already it’s a lot to lug around. And besides, what should a hardware device be able to do that a plugin can’t?