Is there a way to have multiple zone maps for a performance?
For example: One performance might have one zone map for subscriptions and one zone map for single ticket buyers.
Or is there a way to "switch" zone maps after sales have begun?
No to the first question, yes to the second, but with caveats.
Changing seat zoning on existing performances is a feature. This is done through Season Maintenance, and allows you to reassign seats for the available zones on your current zone map. You can NOT change zone maps entirely, but if the number of zones differ between what you have and what you want, you can either discontinue the use of certain zones entirely for those performances, or add zones to the global zone map that is in use, and then apply those new zones to your performances with this function.
This is not to be done lightly however, since lots of the configuration for price zones is done relative to a system-wide zone map, not just a single performance. All you can change per-performance is which seats are in which zone. An example of how we use this function is for premium seating. Our standard zone map has 8 zones, but only 7 are applied by default. The 8th zone is strictly used for premium seating, and is applied per-performance after configuration if we decide to offer premium seating for a performance.
If what you are trying to achieve are different zones for subscriptions/single tickets sales, what you may need to do is create a new zone map that is the product of the two different zone maps. That is, if my subs zone map has rows 1-2 in zone A and row 3 in zone B, but my single zone map is 1 in A and 2-3 in B, what I really need is row-zones 1-A, 2-B, 3-C -- which I can then apply in different groupings to my sub price types and my single price types.