Thanks. You not only avoid the fees every 6-14 months, you also avoid the need to access the master-key, for example in case you’re being paranoid and it’s a multisig hidden in different geolocations.
It’s also good as a recovery solution unrelated to inheritance - in case the master-key was lost, at least the funds could reach a secondary wallet after X days. 
If you run Umbrel, there is nostr:npub1rwj9tlpsp8fs5az59jgk2j6m22w3fuvme47u8deyxv8f86ussxnsgjwl7f that will send you Telegram notifications for all kind of events (It can’t watch an xpub but it can watch individual addresses for incoming and outgoing transactions).
To watch reliably if a transaction-id has been broadcasted, like in the case of a Timelock Recovery plan, you can simply check some blockchain explorer once a week/month.
I’m also considering starting a business that will let customers sign up for notifications on their transaction ids, and if the transaction had been broadcasted we will try to contact the customer in every possible way (even a phone call at 2AM), similar to a “Stolen Vehicle” service that will contact you if somebody is trying to break into your car.