Astonishingly good gameplay loop, bravo.
That's gotta be pretty close to the maximum I think you could get (assuming we're not counting 800, surrounded by mines). If the top left was a corner, you could get 10+7+7 in the top row, both 9s in the next row, then 8+8+11 in the bottom row, for a total of 69 in the middle. I can't think of a way to top that without breaking some level-gen rule, and it would take incredible luck to get there. Getting three 8s would require giving up the 10, and that loses you more points overall.
I'm not 100% sure, but I think you can have only one 9 near a corner, because Romeo and Juliet always mirror each other's positions horizontally. I only noticed that like last week, after a VERY long time just thinking they were on the same row.
So I think the max would be a total of 67.
That's 8+8+8, 7+7, 9+11+9, either middle of 3rd row or 3rd from bottom row.
Or near a corner, 10+11+7, 9+7, 8+8+7. Either way, total of 67.