Speaking in Beancount language, if you wanted to book expenses on the month they’re consumed, you can create an interim account (e.g. Assets:Interim), or even make create a specific account for the counterparty, to which you send the money (e.g. Assets:Assura).
Then, on the date of the payment, you book -1200 to Assets:Bank and +1200 to Assets:Assura. Then on the first day of each month you book -100 to Assets:Assura and +100 to Expenses:Insurance.
I would take a similar approach to depreciating high-value assets (car, flat, bike). You give away money, but get a physical object in the value of that money. And then each month it loses a bit of its value. Then when you sell it, you get money, but lose the object. If you were accurate in predicting the value, there should be no bump in your portfolio value.