Just a brainstorming idea, but would it be too radical (as is being considered for Militia's discard down to 3) if *all* discards were one at a time?
The biggest change, I think, is that you could draw new cards mid resolve that you would choose to discard. A small change would be that your opponents would get to see all your discards.
And I'm sure there'd still be details / ambiguities that need to be answered by FAQ. For example, with Cellar, "discard any number of cards" would mean that you first choose the number of cards you want to discard, then discard them, one by one, resolving any on discard events as you go along.
So with an empty deck you play Cellar and choose to discard 2 Village Greens, you discard the first, play it (putting it in play), shuffle (assuming you chose the draw now option), draw a card, then discard the 2nd, putting it in play, drawing another card; and then you draw 2 cards to finish resolving Cellar.
Are there consequences of this that I'm missing? Would the buff of possibly drawing better discard targets outweigh the benefit of less confusion (playing Village Greens that have been shuffled into your deck)?