Any discussion is good of course, but I think this talk of mental calculations, corner velocity, L/D max, etc. overcomplicates and muddies the waters on how pilots are supposed to use Va in a practical sense when it comes to actual maneuvering. I'm still unable to glean concise and clear advice from this thread unless (consistent with my simple mindedness) the only useful application of Va during aerobatic maneuvering is to recognize that yes you are in fact either above Va and can possibly bend/break something if you have zero feel for what you're doing and pull like a gorilla...or no you are in fact at or below Va and will not pull the wings off if you handle the controls like you have zero feel and no clue what you're doing.
Again, I just don't know any aerobatic pilots who have ever even considered Va while doing acro. It's all about G load and feeling for what G load is most efficient for what we're after, but airframe protection related to the very specific Va number doesn't enter the equation. We simply don't exceed the G load limits regardless of airspeed. Maybe fighter pilots are different. Regarding LD max, this is not necessarily always the goal, depending on what you're trying to accomplish in your aerobatic maneuvering. But again, I'm not connecting this separate topic to Va. If you are letting a newbie or some kid yank your airplane around, it might be wise to limit your speed to Va in case they handle the controls like they're playing a video game, despite your best efforts at briefing them.
Regarding max recommended snap speeds, I've never thought about that in the context of asymmetric G/load and maneuvering speed. Never seen any analysis on it either. Interesting question. Snaps put high loads on the tail and longerons even if min. G is used to initiate a snap. "Rolling G" is easier to visualize and analyze in terms of G load plus aileron use, but snap dynamics are different, since they are not aileron driven and snaps very quickly break and unload. Aerobatic aircraft suitable for snapping typically list a recommended max snap speed and pilots should respect that regardless of what the higher Va (asymmetric or otherwise) number is.