the honda vs mazda comparison really isnt fair. honda engineers vehicles and components to be far more interchangable across vehicle lines making swaps easier by comparison.
honestly, there is no compelling reason to drop a DISI 2.3 into a car that doesn't already have it. its cheaper, easier, quicker to make your standard 2.3 from an 04 mazda3 faster than it is to convert to a DISI setup. plenty more parts available, its a relatively stout engine even stock and you don't have the fuel system handicaps that you would with the DISI. i'd wager to say you'd spend alot less money getting a standard 2.3, building it, boosting it, being faster than a DISI swap.
everything would have to be custom getting this engine into a 3rd gen protege. the engine situates itself in the reverse position that a protege engine does (intake manifold in front, etc) the transmissions are not remotely alike, there is the issue of the throttle by wire system versus a traditional throttle setup, completely rewiring the car, custom exhaust, custom engine mounts, getting the dash to work, all the sensors involved in making the car smog legal, the fuel system...
is this a buzzkill or a nay say or a poo poo on the idea? yes, absolutely. when all is said and done can it be done? sure, with money. how much do you want to spend and what would you like the end result to be? its like when people ask me about doing the AWD swap from a Sport20 to thier protege. the parts alone will put you at the price tag of a used WRX and whats the result? a 130hp car losing power to four wheels instead of just two. Realism, pessimism, call it what you like.
Build the 2.0, boost it, enjoy it.