Include everything in your Revenue; and
Include only recurring contracts/revenue in your MRR.
It’s really that simple. Everything that brings in a dollar this month is revenue for this month. Just segment in. And use stacked charts to show the difference, e.g. 75% of our revenue is recurring, and 25% is from one-off payments, services, per-minute usage — whatever.
Keep it clear, play no games, and you’ll scale easier. If everyone isn’t 100% sure of definitions or even what your revenue is … that’s a problem.
All your revenue doesn’t have to be from recurring software. It’s OK.