Yes agree, but installing a new bottle and pipes by diy at worst would be a cross threaded or loose pipe I guess, and not in a confined space…Propane pressures are much higher than domestic gas. If a corroded tank or perished pipe ruptured the gas could erupt in a spectacular fashion. A small spark might be enough to set off a BLEVE (Boiling Liquid Expanding Vapour Explosion) and you really don’t want to be anywhere near if that happens.
agree, smoking etc whilst doing it would be a bit daft….