https://www.tecumseh.ca/en/living-here/ ... Report.pdf

Is it possible to cut it with distilled water, say 50-50 for no scale?

That report is missing key numbers for chloride and for hardness, but the alkalinity numbers look OK for a 50:50 distilled dilution, and most likely that would be non-scaling. You would want to watch for evidence of scale because it depends on calcium hardness, alkalinity, pH, and boiler temp. And if the chloride ion is high it would be much better to use pure distilled with a spike of bicarbonate rather than diluting this water.