Is this for some linked brakes application? On my 5th gen vfr, when I swapped the engine , dealing with the brake plumbing took as much time as rest of the frame swap :laughing. At one point I was ready to rip it all out and de-link the brake lol
Touching on that point, on the VFR the circuit that activates the additional pistons due to linked system is independent of the main brake circuit. I assume this will be typical of most linked systems. Check the service manual for your bike. Just pointing it out in case that changes your stand on DIY. So, on my bike an unlikely leak in the linked system won't cause the main 4 pistons (per caliper) of the front brakes to fail.