The two child limit, and associated rape clause, is punitive. If we look at UK families with three or more children, two million of those kids are in poverty [1]. Scrapping the limit would cost a token amount, and lift 270 000 [2] children out of poverty.
[1] https://www.gov.uk/government/statistics/households-below-av... table 4_5db
[2] https://edm.parliament.uk/early-day-motion/61220/the-twochil...