Persistence and runtime of switch

I have several switch objects i want to see the runtime on.
I know that i can do this with an additional item and rules.
Would it not be nicer to have a .runtimeSince extension in persistence?

What exactly would you expect the answer to be?

A common approach is to select one the persistence services that iscapable of storing on/off as 0/1, configure it to persist every minute, and when required use sumSince to add up minutes “on”.

Yes but then i need to store much more data.
It would be a simpler for more users if it was a persistence extension.
I can solve it with SQL from script.