So, this item can be moved to next May milestones.
Initial focus was shifted from adding features to first work on the error handling. Some ground work was done there (status-im/nim-eth#231) but more is to be done.
I'd close this instead of move as the last item is handled here: status-im/nim-eth#266
And while not all tests mentioned in that test item are handled, several other (not mentioned are).
So probably better to create a new item with which discovery items to handle.