the new emplode doesn't find my player on ethernet, while the old emplode quite happily connects

This could be a problem if your unit isn't on the same subnet as the machine running emplode. Is this the case?

If there's only one empeg player found, it would be nice if OK (or enter) would select it by default.

Fixed. Should appear in the next release of the preview, assuming we've not rolled it all together by then.