If your garden is that size then a boundary wire system is very manageable. You got any tricky elements? Ponds, step slopes etc?

Also while I’m fully in favour of HA integration that is going to push the price up. But what’s the scenario you want that for? Robomowers are a good fire and forget application. No integration needed, but if you really must there are some easy modifications involving the rain sensor that can give some limited control.