Question is: Do 2 10A fuses in parallel make 1 20A fuse?
I would have thought not as both fuses wouldn't be exactly the same spec and so path of least resistance would be taken.
I could be wrong... I could be right as Mr Lydon would say
Then the one drawing more current heats up more, slightly increasing its resistance.
I can imagine some kind of feedback loop happening.
Would never not blow over its 20 amp rating, but could also certainly blow under it.
Its a safety, safety fuse.