I do this with shared schedules.

I've got about six shared schedules which are triggered at various times in my etl process.

I have a stored procedure which is triggered with a parameter indicating which shared schedule should be executed. The proc then reads the db to find the subscriptions associated with tht schedule and does this add event trick.

That way, we only have to assign a report to a shared subscription and it will go, no extra set up necessary.

It's been very stable for a couple of years now.

Honestly, this really shouldn't be so difficult a task to manage. It should be base functionality of the product to make ths process easy. No one dealing with etl processes is going to be able to schedule a report at a given time and be assured the data will be ready.