We all know that too low a temperature and filament is not sticking well together, we also know that too high a temperature and filament burns resulting in both cases low quality print.
We also know many filament materials lile PLA cannot be printed together with other materials although same melting temperature ranges, because they simply do not weld to each-other.
He understood what most of us did not, that is an advantage, not a disadvantage.
Naturally this would not work for internal supports, those must be dissolved with a solvent that works fine with sports materials but has zero effect on the filament of your finite part.
However considering the cost of PVA support filament, or if you think you go cheap with HIPS, remember the price of Limonene solvent is not that cheap. same if you want ABS support remember the price of Acetone solvent is not cheap at all, use them for interior supports that you cannot mechanically remove, and print your external supports with some cheap incompatible filament with the main piece.
Obviously that requires you to have a cyclope heater, or a diamond heater or a changing tool or a multiple nozzle independent system like I do now with my home made dual that is soon to become full metal quad nozzle block.