I personally would not feed, nor I would feed silversides. There's no need to "test" a recovery and it might put an extra strain on a nem that's using energy to acclimate. Nor would you want to add waste to the tank, even though water changes are done regularly.
I would stick with human grade food if you choose to try. As we discussed on a few threads prior, some have attributed a bad (spoiled/rotten) silverside as the cause of the death of their anemone. IMO, I don't think it's worth the risk when there's no benefit to feeding silversides over other foods. My food of choice is a small cube of salmon soaked in Selcon (or other vitamin enrichment). If you have access to needles, another good suggestion I read was to inject them with Selcon.
BTW... the haddoni looks great. Keep up the good work.