So the upgrade from 2013-2015 front brakes to 2017+ is completely bolt on. My fear of the brake lines being too short was unfounded as well. The part numbers for everything except the caliper bracket and rotor are exactly the same. The pads are even the same.
My sister's 2015 stops as well as my 2018 now.
-Mitsubishi 4605B101 Caliper Bracket - In my opinion check car-part.com and get some salvage ones, I got the entire caliper, bracket, hose, pads, ect from a 5k wrecked 2018 G4 Mirage for $50/pair. I have a buddy with a 15 Mirage that may need calipers down the road, so I'm keeping those around.
-RAYBESTOS 982091FZN Rotors - These are a good daily driver rotor and are coated with a rust preventative.
Brake jobs on these cars are extremely easy, but this will also give you a few pictures and a how to on disassembly as well.
1.) Remove the caliper bolts (2x), then the bracket bolts (2x). The front pad is clipped into the caliper with two nubs which you will need to carefully pry out and the rear pad just sits in the caliper and should slide out. Hang the caliper somewhere where the hose does not have any undue pressure on it.
You can then remove the rotor. If you have any trouble with this make sure to grease to hub face to make future rotor replacements easier.
2.) Install the new bracket, pictured is a side by side comparison of the increased size of the newer brackets.
Here is a side by side of the old and new rotors. Notice a solid 1" difference in diameter.
3.) Slide the rotor back on, reinstall pads making sure to lubricate any touch points on your pads and clean/lubricate your slide pins with silicone grease/brake lubricant. (DON'T USE ANTI-SEIZE, it is oil based and will break down the rubber bushings on your upper slide pins.) Now you can go test out your new brakes, but make sure to pump your brakes a few times do you don't go flying out into the street.
Keep in mind that unless you complete the break in procedure you may have noise or decreased stopping distance until the rotors and pads seat.