I'm guessing that "meter tape" is slang for painstakingly printing meter increments onto a piece of tape to be placed on one's monitor (like a putter pal) but used for ALL clubs, from driver through wedges.
As for putting percentages, I read (and tweaked) a forum math set that held slow = 1.25 x, standard = 1.15 x, fast = x, Very Fast = 0.85 x, and tournament greens = 0.75 x with x being the net distance of feet + or - inches uphill/downhill, but on slightly uphill putts, add at least one extra foot because you are fighting gravity.
The tweak I added is that on long downhill putts upto about 6 inches declination, subtract an additional foot for every 15 (Ex. 109 footer I made was downhill 5 inches. So the net was 104 which, at tournament speeds meant 0.75 times 104 =76, but 109/15 =7+ so I removed an additional 7 and putt the ball 69 foot strength, and you can view the replay on my profile page - it just kept going and going and never looked like it would get there ... but it did. The aim was (of course) dumb luck, but an experienced aim, nonetheless.
But that tweak doesn't exactly work for uphill putts, which I have yet to find a consistent formula by which to hit the correct distances on the dot, no pun intended.
If you find "the" tweak, please post it here as a reply (TY).