Ime , 1 cartridge of di 700ml will only make 350litres of 0tds water. After that tds will rise.
Price of di resin not cheap also at 9$/litre di resins.
Rodi still much more cost savings imo.
Di resins in ro unit can last 8-10months Time if weekly make 50litres. Waste water can flush toilet , mop floor , water plants , wash clothing (topload) etc.