Instant File Initialization on Backup drive
If the archive location is part of same server and if you are performing restores to same server,then you will have IFI enabled.You can always enable Instant file initialization on server you are performing restores too ,I dont see an issue enabling it on prod server and not enabling it on test server.you can further check using below trace flags if IFI is enabled or not.

DBCC TRACEON(3004,-1);
DBCC TRACEON(3605,-1);