Tesla does not recommend charging to 100% on a regular basis, but only for log trips. Not sure if this will be the case for Rivian, but at least from what they posted in the Charging Story, it may be ok to “top off” (100% charge?) regularly:
Instead of running down your vehicle towards empty before stopping to refuel, you can top off each night so you have plenty of charge for the next day. If you forget to charge or choose to skip a few days — it’s ok. A daily commute won’t come near the amount of range you’ll have.
We are building the Rivian Adventure Network — a nationwide network of DC fast chargers capable of adding up to 140 miles of range in 20 minutes to the R1T and R1S. The Rivian Adventure Network is designed for quick recharges so you can keep moving. Planned to connect cities on popular routes...
stories.rivian.com