Hmmm, while I see the use case, we don't like to add time-based event too much because they cause load on the chain. This would be something could be automated through an L2 (for RC, HP requires an active key which is no go).

As for the HP I'm like, why is it a problem ? People are free to do what they wish with their stake, if they wish to delegate then go MIA well it's their choice. It was bad for governance votes because it directly affects things like witness rankings or proposals but for delegations it has a lower impact (if you want to mention people self voting and such, I'd say abuse can be countered with free downvotes or by various initiatives)