Whoever first decided to make quince jam was either very hungry or determined. Probably both. I wish I had though to take pictures during the messy process of cramming 7 pounds of quince through a very small strainer.
2 words - Steam Juicer
I used to run my cooked plums through a china cap style strainer with a pestle. It took forever and made a huge mess. I got a Mehu-Liisa steam juicer. Took my labor from 4 to 6 hours per case of pints to 4 to 6 hours per 4 cases of pints! I use the bottom pan for everything so it isn’t a uni-tasker. Try it, you’ll never go back to the old way.