1) is -- correct?
2) either way it should be weighted as 0

I don't think "unknown" should be considered same as 0. If you display 0, you are stating that you know the expected returns percentage for that validator, but in this case we don't know
The rewards should display though as @mariopino implemented that already
Validators with -- rewards were not online in the last era.
I also think that displaying -- is the best way, as we need to distinguish from i.e validators with 100% commission which gives you an effective 0% reward.
I think the problem is that the default validator order is reward (desc) and we are showing those validators on top, which is maybe not super effective.
Maybe we can tweak table ordering to place -- at bottom?
Validators with
--rewards were not online in the last era.I also think that displaying
--is the best way, as we need to distinguish from i.e validators with 100% commission which gives you an effective 0% reward.I think the problem is that the default validator order is reward (desc) and we are showing those validators on top, which is maybe not super effective.
Maybe we can tweak table ordering to place
--at bottom?
Returning an empty string instead of undefined in API for expectedReturns seems to do the trick, placing -- after 0% in validators table.