Victron inverters have 2 outputs so you can program one to work only sometimes depending on logic, but idk if victron makes sense as its expensive
If no other options you can easily automate it with smart home tech like homeassistant. a simple 15a smartswitch and logic to only turn on when batteries are charging or at x percent. Would be cool to have it charge the mower when batteries are like 80% then you're basically using excess solar to charge