This past June my RT-600 remote tuner failed. I know it was out of warranty and discontinued and with COVID affecting everything I did not expect a quick response back. In September I emailed them inquiring the status and they said it was non-repairable and offered to send me the AT-600 ProII or another model as a replacement for free and I took the 600 Pro II.
This was great and I really appreciated their customer service. That's how you gain customers and retain the loyal ones.