I think this is a non-problem now. As of now, you want to grow your user base as much as possible. Since all your users are paying, you are not carrying a dead weight of freemium. Build up user count by any means possible. Only once you will see a significant drop in growth of revenue try to upsell current user base by adding important features.

Keep, for example, Cloudflare in mind. They have first built their user base, and once they were used by thousands of companies, they started offering additional options, Enterprise ($2K+) accounts etc. Focus on growth first, and keep some aces in your pocket for the time your revenue will stall. This way you will be able to be innovative whenever growth is slow, and there is a possibility a competitor will show up and take your business.