There are overhaul kits for power steering pumps and you can see them when you check the diagram of the car on partsouq with your vin. The kit would probably cost more than a kabali pump though.......but on the other hand you may get a longer life.
As for the cvt fluid, the Diaqueen atf sp3 is designed for use in gearboxes only. It’s not suitable for power steering. For power steering you should use fluids which either expressly say that they are safe to use with transmission and power steering such as Liqui Moly Toptec 1200G or you get fluids which express say power steering fluid on the can such as Honda Power Steering fluid.
Our desi mechanics are champions in replacing parts prematurely. I believe flushing your PS oil and lubricating the steering rack should solve your problem. Otherwise you can reuse the new oil whenever you get the pump repaired/changed.
Another common example of mechanic prematurely replacing parts is brake pads and shoes. Most mechanics recommend a pad/shoe change with 50% life left. Mitsu itself recommends front pads to be changed when thickness falls to 2mm or below 2mm. And I’m not sure about the rear shoes but I think that is also either 1mm or 2mm. I got my brake pads changed in 2016 and in 2018 my mechanic recommended changing them. I ordered new ones but then also found the FSM of lancer. I read up regarding the brake pad threshold above and decided to run the pads down to 2mm or lower. The pads were finally changed in Jan 2021 after a life of 65,000 km.