Amp Gauge "Sorta" Bypass Question

Del @67Dart273 and other electrical gurus. I want to run a heavy gauge wire from alternator positive to the big lug on the starter relay. I've had NO issues whatsoever with the stock wiring, the firewall connector or amp gauge. I want to keep it that way. Will doing this help "unload" the amp gauge and help curtail any possible problems? I realize the amp gauge will not read "correctly" but I believe it will still read "good enough" to see that it is charging or discharging. Is all of this pretty much correct? Also, what gauge wire would be recommended?

Thank you drive through.