Can the solar controller be graded?

Yes

1. 2020 model just upgrade the controller. All existing wiring stays the same. The controller is behind the refrigerator.
2. To upgrade to Victron, the controller can be upgraded, but the controller panel will need to be upgraded causing cosmetic for remote controller and possible remote wire change. May want to move closer to the batteries, may require splicing in a extension cables to the existing cables.

Can the Sine wave inverter be upgraded?

1. May not need to. It is already a pure sine wave inverter.
2. Yes, like the solar controller, it would be a drop in replacement but the remote controller would need to change.
3. Move to a hybrid converter/inverter. May need to pull wires through the driver side tunnel.