Can we have a translator switch to a different primary station at times during the day?

No. A translator must rebroadcast the primary station that it is associated with. 

If a translator changes their primary station, a Primary Station Notification must be filed with the FCC to advise of the new primary station. FM translators that were applied for in 2017 and 2018 during the Auctions 99 and 100 filing window (AM Revitalization) are permanently "married" to the AM stations they were applied for and cannot change their primary station.