I've made some changes to the Renko_2 indicator for MT4 so that it uses the ATR(14) to figure the box size instead of an automatic 40 pip or either a user entered amount. Didn't mess with the meat of the code, but I did put in a section that determines how many decimals the pair has, then uses the ATR to figure the box size. I've checked it on 4 pairs and it seems to work fine but not sure how it will act when the ticks get turned on tomorrow.
There's probably a hundred different ways to skin this with the ATR. I just now thought while typing that the safest way is probably to use the ATR value from the last peak instead of the 14 period ATR but that's some coding for a different day.
I've put them together in the chart below. The one hour doesn't show a huge difference, but if you throw up a 5 min the difference is huge. Different pips and timeframes, different box sizes. DL link below the chart.