Once you have shorted out the 5 Ohm resistor, it really doesn't matter if you leave it there or clip it out.
However, I have no idea as to the validity of that "fix". Without doing some reverse engineering I cannot provide any input into what that modification does or if it's really a good idea or not. The guy in that video seemed confident in it, but I'm not confident in his confidence.
He said something about "running the numbers" and "that resistor in there reduces the voltage"... Well, without seeing a schematic, I'm not sure at all what that means. Might be harmless, might not.
Is this a common thing that a lot of people mess with? I might have a spare tach around here somewhere...