I believe the zylenox thing was a specific rule. It only has to do with calculating where the stronghold is, IIRC it's because when they banned calculators, they realized people could just do the same thing calculators do with pen and paper, so they wanted to discourage that by adding it to their final time. This type of restriction has not been added to other things yet, many runners pause in the middle of their runs to do stuff like this without it being counted towards their final time.

why not just use sodium lithium and phosphor?