new wires for the Mamba Max

I have had my MM for little over a year now. I feel the wires are limiting the MMs performance. Ive hardwired 2 motors to the esc before, using the same wire for both motors, i thinks its time for fresh wire. after a run, i would feel the temp of the wire & the esc, both getting fairly hot, & i run in temps of 30*C+. I will be using a fan for the esc to help lower temps. but for the wire, Im planning to use the new Silverworm wire from acer racing with lead free solder.

Now, i was looking on the forums & found a few threads regarding soldering wires to the MM PCB. I use an 80W iron & the wires came out of the solder tabs with ease. to fit the 12awg into the solder tabs, i plan to use a reamer to ream the holes out a bit so the 12awg can fit through properly. should i use flux?

Now, is there anything else i should consider besides watching how much heat is applied to the esc's board? of course i know doing this will void my warranty, my warranty had expired at the start of this year. Is there any real advantages of running 12awg wire besides it being thicker & that they can flow more current? My MM is paired with an orion vortex 7.5 (no cogging) & i use 4700 & 4800 2S lipos, its used in an on-road drift chassis so its not powering a heavier offroader...