But, then I thought through another idea I had earlier, and a "better way" became obvious. The idea is to use an ask-or-answer approach.
Consider a simple auction. 2♣(strong, artificial)-P-2♠(spade positive)-P-4♥(spade fit, shortness in hearts). Now what?
Using the "ask or answer" approach, Responder could bid 4NT as RKCB with the heart Ace, making the void showing irrelevant, or less relevant. Without the heart Ace, Responder "answers" and bids 5♣...5♠ as his hypo key card answer to a hypo 4NT from Opener, but without the heart Ace.
How about another situation. Hearts are agreed. One person has shown shortness somewhere. 4♠ by his partner denies the missing Ace and is an ask-or-answer relay. His partner can then bid 4NT as Exclusion (void or stiff Ace) or answer (singleton). 4NT instead of 4♠ is RKCB but promises the Ace in the short suit.
This allows the RKCB responses to stay at the normal level but resolves the "stiff or void" question "before" the answers. This approach suffers from the loss of other meanings for the five-level calls and, accordingly, should probably only be used in pre-discussed auctions or types of auctions.
An example from real life.
Opener: ♠AKJxxxx ♥Kxx [D]AQx ♣void
Responder: ♠Q10xx ♥AQx [D]Kxx ♣xxx
2[D]: 22+ or 9+ tricks, 4+ spades, unbalanced
3♥: Power spade raise, Qxxx+ or xxxxx+ support, very good hand
3NT: 6+ spades
4♣: Shortness ask
4♠: club shortness (minimal LTC)
5♣: one(1430), no club Ace
5♥: King of hearts?
5NT: yes, but no diamond King
6D: diamond Queen?
6NT: yes, but no heart Queen
Compare that with the auction up to the 4♠ call and 4NT as just RKCB. Opener has a 5D response (0/3). He jumps instead to 6♣ to show the void and 0/3. Responder can ask for the heart King (6♥) but not the diamond Queen.