Is anyone aware of a way to more granularly control Data View options for Landmark transactions after the October CU was applied?
According to support, once the CU was applied the only way to use Data Views on a Landmark transaction is to enable the disableDataViewOffV2 config parameter, which will revert to the pre-CU behavior. However with this config parameter enabled any Landmark transactions that aren't set to "Execute via Web Service" and have "Use Data Views" set to "DEFAULT" will use data views.
There are some types of Landmark transactions that still require data views, e.g. SystemCalendar.CreateDates, so it seems like the only option to still use data views selectively is either enable update all of your flows and set "Use Data Views" to "NO" on all transactions that aren't "Execute via Web Service" except the ones that need data views and leave the override config parameter enabled, or toggle the config parameter inside the flow when data views are need in a transaction.