Is Multi-DB is a viable solution with 4.7.2

We have been using a multisite WordPress configuration for over four years. Recently, demand for host sites on our system has increased 3 fold. We event from 50 active sites to 150 over the last year. We know we could go way beyond that number.

We have been doing this with a single DB and the systems is dragging. We haven’t had a need to do a re-architecture until now. We know we need to use multiple databases, and mostly multiple servers, but can’t find a definitive guide to doing this. I know from various articles that Multi-DB is a solutions, yet it’s no longer being updated. Is there another solution or does Multi-DB still run with 4.7.2?

Thanks