@dracop, valid point when talking about heavier weight in overpowered conditions! At same load, line raw material and factory pre-stretching a thicker line has normally lower elongation than a thinner line.
There are exceptions though. Both these are SK99 lines. At 80kg load the 600+ kg line has 0,8% elongation vs 0,5% for the 400+ kg line. That's 11-18cm (4 - 7in) on 22m lines. When a 100kg rider has 160kg load on both lines I haven't measured yet
But one thing is certain - the thicker line will have higher residual strength than the thinner after same exposure to abrasion. And let's not forget that the thicker line exhibits less abrasion wear due to higher contact surface area when rubbing against another line (crossed lines case).
Just did some waxing with candle dissolved in Zippo lighter fluid (petrol/gasoline) and liquid ski wax. Easier to apply and I guess better penetration than hot wax. The main benefit I see is in waterproofing old soft lines with no coating left. Less salt water absorption, less shrinkage. Whether these waxes will pick up sand I can hopefully test in few months, but personally I'm not interested as I have more new lines than I can use in the next decade.