I've used pure butane, butane/propane mixes, and propane in Accucraft locos with poker burners. They all worked fine. I've used butane, butane/propane mix, and propane in my ceramic burner with no trouble.
The only concern I've ever had is that if your gas tank was designed for butane, then using pure propane would/could be dangerous since the pressure of propane is much greater than that of butane. The mixed gasses pressure is between butane and propane, and your gas tank may or may not be able to handle it in warm weather. If you steam in cold weather, then butane won't work because it's pressure becomes too low (about 0psig at 30degF). That's when I use the mix; I have a chart telling me the pressures of mixes at various temperatures, so I can be sure that I don't inadvertently overpressure a tank.
When I use pure propane, I use the 1 pound bottle commercially made and supplied for propane torches; that way, there is no danger of propane splitting a tank seam. The only disadvantage to propane is that your craft must be big enough to hold a 1 pound tank.
In theory, the nozzle size should be changed for different gasses. But in practice, it does not seem to matter whenever I've steamed my models. Ditto the airholes.
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If you are using a refillable gas tank, then refueling from the butane cylinders should not require an adapter. You just press down on the refill valve in your gas tank with the smooth nozzle of the butane cylinder. The adapters shown on the mineature steam site url you gave are used, in the US, for butane/propane gas mixes, and are, essentially, a way to mimic the plain smooth nozzle of a butane cylinder.