"What is different about the K-1 than the 1099-DIV?"

You are now a partner in a partnership, you're not an owner of "shares" of a corporation.  Partnerships do not pay income taxes.  Instead they "pass through" to their partners all of their economic activity, reported on Schedule K-1 and the partners then enter this economic activity in their own personal income tax returns.  Accordingly, partnerships don't pay "dividends" they make "distributions" and most commonly these distributions are treated by the partners as a reduction in the basis in the partnership.

So I'd say an amendment is in order.

You'll have to sell and re-buy if you want to hold this ETF in your Roth.  You can't do in-kind contributions.

Tom Young