Did a bunch of optimizations to try and get performance back to where it was, most of which had little or no effect. Then added spritebatches which speeds up love 2d if the same sprite is rendered multiple times at once. This resulted in more than a 100 fps speed boost.

I had thought about trying spritebatches a few days earlier but held off because felt I lacked free time to implement it. In practise It took minutes by using the lib https://github.com/rxi/autobatch . I had to slightly modify to work with love 11.x but it was just a few minutes work to get night and day results.

Enjoy :-)