That's seriously bad advice.
The majority of sailors who would set and forget their tension have no idea how tight it should really be, and what that feels like. A gauge or a system like the folding rule allow them to get it right.
Most have it set too loose. Too tight is better for the boat than too loose.
Actually, overtensioning the rig is not better for the boat, and it's not fast. Rigging wire is susceptible of a very small amount of stretch. If you overtighten the rig, you'll quickly reach the point where you have stretched it to the maximum. If you tighten it beyond that point, you'll put too much of a load on the chainplates. I have seen the transom gel coat cracked when excessive backstay tension was applied. After you have taken all the stretch out of the wire, if you continue to apply an increasing amount of tension, something has to yield. If the wire can't yield, then the fiberglass will probably yield at the points of attachment.
A boat's ability to point is primarily determined by the boat's geometry, and by the cut of it"s sails. If you have adjusted all the sag out of the forestay, and then continue to overtension it, that won't make it point higher or foot faster. There's a point of diminishing return. Moreover, the whole purpose of a backstay adjuster is to enable you to change from a taut rig to a loose rig, and back, on the fly.
Like Bob Perry, I have also raced very successfully for many years, and have never used a Loos gauge to tune the rig. It isn't difficult to learn how to tune a rig without a tension gauge, but, like anything else, it takes some time and experimentation to hone your skills, and you have to be conscious of the basic goals of rig tuning. A good place to start are the Giulietta and Selden articles, referenced by RichH.
Don't be intimidated by the apparent complexity of those discussions. Think about the most basic goals of rig tuning. Generally, if the mast is erect and in column, and it can't move excessively; and, if the rake of the mast gives the boat a light weather helm, and the backstay adjuster allows it to change from taut to loose, then the boat will at least be competitive within it's class. Overtightening it won't make it any faster.