I believe that you should be rewarded a dividend based on the fees collected from the market on the days in which you held your market pegged asset (such as bitUSD) for. If you can just earn the full month's dividend for holding bitUSD at the moment of the scheduled dividend, then there wouldn't be an incentive to hold your FIAT savings long term on the BTS DEX (the primary point of dividends for MPA, encouraging more BTS to be locked up as MPA collateral).
UIA would have the option of whether or not they wanted to enable coin-age in their dividend distribution, OBITS for example doesn't take coin-age into account when they perform a dividend.
I get your point. Incentivizing is fine. But don't let it get in the way for actually paying dividend. It is not common practice in stocks that is the asset class I know best. The way I view this proposal is another delay, which I would be plain, downright boring.