You can also disable LogSync. SnapSync will always gets the logs it needs to make a snapshot recoverable (and therefore able to make VDBs!)
You could disable LogSync and run SnapSync every hour if you like, and that would give you 24 recovery points a day and saves space on your Delphix engine.
Finally, you can have separate retention for logs, for example 90 days of snapshots and 2 days of logs would give you point-in-time recovery for a couple of days, and less granular options for a long duration.
Just to complete Ranzo's update and give you some tracks to explore.
To achieve your need explore one of those options if possible :
1) Ask customer to change the purge/backup policy of archivelogs (hard to negotiate because of customers reasons SLA, HDD space ...)
2) Configure delphix to take frequent snapshots lets say every 50min if the customer policy is 1 hour, but you will end up with a lot of snapshot cards 29 per day
3) Just ask customer to introduce a call to delphix api to take snapshot before archiving ARCH files
2 and 3 are similar only the way changes
4) Delphix livesource (aka. virtual dataguard), you will not have to worry about arch as you will be synced with redo